Multiplying and dividing negative numbers
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Multiplying positive and negative numbers
Basics of multiplication with negative numbers
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 We know that if we were to multiply two times three,
 that would give us positive six.
 And so we are going to think about negative numbers in this video.
 One way to think about it,
 is that I have a positive number times another positive number,
 and that gives me a positive number.
 So if I have a positive times a positive,
 that would give me a positive number.
 Now it's mixed up a little bit.
 Introduce some negative numbers.
 So what happens if I had negative two times three?
 Negative two times three.
 Well, one way to think about it
 Now we are talking about intuition in this video
 and in the future videos.
 You could view this as negative two repeatedly added three times.
 So this could be negative two plus negative two plus negative two
 Not negative six. Plus negative two.
 which would be equal to
 well, negative two plus negative two is negative four,
 plus another negative two is negative six.
 This would be equal to negative six.
 Or another way to think about it is,
 if I had two times three, I would get six.
 But because one of these two numbers is negative,
 then my product is going to be negative.
 So if I multiply, a negative times a positive,
 I'm going to get a negative.
 Now what if we swap the order which we multiply?
 So if we were to multiply three times negative two,
 it shouldn't matter.
 The order which we multiply things don't change,
 or shouldn't change the product.
 When we multiply two times three, we get six.
 When we multiply three times two, we will get six.
 So we should have the same property here.
 Three times negative two should give us the same result.
 It's going to be equal to negative six.
 And once again we say, three times two would be six.
 One of these two numbers is negative,
 and so our product is going to be negative.
 So we could draw a positive times a negative
 is also going to be a negative.
 And both of these are just the same thing with the order
 which we are multiplying switched around.
 But this is one of the two numbers are negative. Exactly one.
 So one negative, one positive number is being multiplied.
 Then you'll get a negative product.
 Now we'll think about the third circumstance,
 where both of the numbers are negative.
 So if I were to multiplyI'll just switch colors for fun here
 If I were to multiply negative two times negative three
 this might be the least intuitive for you of all,
 and here I'm going to introduce you the rule,
 in the future I will explore why this is,
 and why this makes mathematics moreall fit together.
 But this is going to be, you see, two times three would be six.
 And I have a negative times a negative,
 one way you can think about it is that negatives cancel out!
 So you'll actually end up with a positive six.
 Actually I don't have to draw a positive here.
 But I write it here just to reemphasize.
 This right over here is a positive six.
 So we have another rule of thumb here.
 If I have a negative times a negative,
 the negatives are going to cancel out.
 And that's going to give me a positive number.
 Now with these out of the way, let's just do a bunch of examples.
 I'm encouraging you to try them out before I do them.
 Pause the video, try them out, and see if you get the same answer.
 So let's try negative one times negative one.
 Well, one times one would be one.
 And we have a negative times a negative. They cancel out.
 Negative times a negative give me a positive.
 So this is going to be positive one.
 I can just write one,
 or I can literally write a plus sign there to emphasize.
 This is a positive one.
 What happened if I did negative one times zero?
 Now this might seem, this doesn't fit into any of these circumstances,
 zero is neither positive nor negative.
 And here you just have to remember anything times zero
 is going to be zero.
 So negative one times zero is going to be zero.
 Or I could've said zero times negative seven hundred and eightythree,
 that is also going to be zero.
 Now what about twolet me do some interesting ones.
 What aboutI'm looking a new color.
 Twelve times negative four.
 Well, once again, twelve times positive four would be fourtyeight.
 And we are in the circumstance where one of these two numbers,
 right over here, is negative. This one right here.
 If exactly one of the two numbers is negative,
 then the product is going to be negative.
 We are in this circumstance, right over here.
 We have one negative, so the product is negative.
 You could imagine this as repeatedly adding negative four twelve times
 And so you will get to negative fourtyeight.
 Let's do another one.
 What is seven times three?
 Well, this is a bit of a trick. There are no negative numbers here.
 This is just going to be seven times three.
 Positive seven times positive three. The first circumstance,
 which you already knew how to do before this video.
 This would just be equal to twentyone.
 Let's do one more.
 So if I were to say negative five times negative ten
 well, once again, negative times a negative.
 The negatives cancel out.
 You are just left with a positive product.
 So it's going to be five times ten. It's going to be fifty.
 The negative and the negative cancel out.
 Your product is going to be positive.
 That's this situation right over there.
Be specific, and indicate a time in the video:
At 5:31, how is the moon large enough to block the sun? Isn't the sun way larger?

Have something that's not a question about this content? 
This discussion area is not meant for answering homework questions.
Can anyone think of any ways to connect multiplying two negative numbers with a realworld application? or how to actually SUPPORT WWHHYY two negatives produce a positive with multiplying/dividing?
Thanks!!
Thanks!!
Real world example (more or less):
A company wanted to encourage sales of its "fuzzy wigets" by offering a $3 rebate to the first 1000 customers to send in the rebate forms. The company's financial computer input was set up so that the total rebates were calculated as a negative number and money was allocated for the amount needed.
3 x 1000 = 3000 $3000 allocated for rebate use only.
Unfortunately, the printer had problems and no rebate forms were printed, so no rebates were given. In order to use the program to reallocate the money, the number of customers not using the rebate program had to be entered as a negative number.
3 x 1000 = 3000
$3000 could now be reallocated for other uses.
A company wanted to encourage sales of its "fuzzy wigets" by offering a $3 rebate to the first 1000 customers to send in the rebate forms. The company's financial computer input was set up so that the total rebates were calculated as a negative number and money was allocated for the amount needed.
3 x 1000 = 3000 $3000 allocated for rebate use only.
Unfortunately, the printer had problems and no rebate forms were printed, so no rebates were given. In order to use the program to reallocate the money, the number of customers not using the rebate program had to be entered as a negative number.
3 x 1000 = 3000
$3000 could now be reallocated for other uses.
well you might use it to calculate the amount of interest you get in your bank account?
a number times 1 means the opposite. So if I owe you $3 and we negate this term, using debt times 1 then you owe me $3. Any negative number can be written as equal to 1 times the positive equivalent. So 5 = 5 times 1. That means it is the opposite of 5. If I make a calculation with a negative number I am negating terms. Look at e.g. 5 * 6. This is the same as (5*6)*(1*1). This is the same as 30*(1*1). 1 * 1 is the opposite of the opposite, and that is clearly nothing. That's like moving 30 steps to the left and then 30 steps to the right. You end up in the same spot. That is why 1*1 does nothing. And because of the equivalence in any negative number to 1*positive this is true for all numbers.
if you do 7+9 it means you are adding 9
Here's why multiplying negative numbers return a positive result:
We know 10*3 = 10+10+10 = 30 and 10*3 = 10+10+10 =30
So why is 10*3 = +30 ?
If I lack 10 apples (10) three times (3) then 10*3 = 30, I lack a total of 30 apples.
But if I lack 10 apples (10) negative three times (*3) then it means for three times I DON'T lack 10 apples (310 > ()the negation of 3*10, meaning not 30, but 30!) therefor I HAVE ten apples for three times = 30 apples.
Hope this helps you picture it! (I answered that before I think but it was moved, so here it is again)
We know 10*3 = 10+10+10 = 30 and 10*3 = 10+10+10 =30
So why is 10*3 = +30 ?
If I lack 10 apples (10) three times (3) then 10*3 = 30, I lack a total of 30 apples.
But if I lack 10 apples (10) negative three times (*3) then it means for three times I DON'T lack 10 apples (310 > ()the negation of 3*10, meaning not 30, but 30!) therefor I HAVE ten apples for three times = 30 apples.
Hope this helps you picture it! (I answered that before I think but it was moved, so here it is again)
it works because two negatives make a positive, say 8 + 8 =0 right? so take  8 x  8 = 16 divide that and you get 16 simple!
This is one of those times where math works for rules that make other things in math work, not because it has a corollary in everyday life. For example, two wrongs don't make a right. In Old English, multiple negatives meant increased negativity so, "Never, not done," meant absolutely not done. These things show life as multiple negatives being negative. However, math has a life of its own and the rules made for math were done so that things work in all cases. If it does not work every time, then there is a problem with the rule in mathematics.
What is funny is, this is not easy to answer. Here is a guy at North Carolina University doing his best, and failing:
http://www4.ncsu.edu/unity/lockers/users/f/felder/public/kenny/papers/negative.html
He was asked about multiplication of a negative and a negative and most of his answers are about a negative and a positive or about addition, not multiplication.
This is something that came about in Ancient Mesopotamia, Babylon, or somewhere like that. It is around 3000 years old... and we still don't have a great explanation that everyone accepts and agrees upon right off.
That may be odd, but Zeno asked a mathematical question, one of the famous Zeno's paradoxes, that could not be answered properly for 2400 years until Newton and Leibnitz developed Calculus!
Sometimes math is just put together a certain way because it consistently works that way. This is a proof by induction and a very deeply argued point of philosophy. This, sadly, leaves a few things to just be taken for granted or forces a person to become a philosopher so they can more properly argue about them.
What is funny is, this is not easy to answer. Here is a guy at North Carolina University doing his best, and failing:
http://www4.ncsu.edu/unity/lockers/users/f/felder/public/kenny/papers/negative.html
He was asked about multiplication of a negative and a negative and most of his answers are about a negative and a positive or about addition, not multiplication.
This is something that came about in Ancient Mesopotamia, Babylon, or somewhere like that. It is around 3000 years old... and we still don't have a great explanation that everyone accepts and agrees upon right off.
That may be odd, but Zeno asked a mathematical question, one of the famous Zeno's paradoxes, that could not be answered properly for 2400 years until Newton and Leibnitz developed Calculus!
Sometimes math is just put together a certain way because it consistently works that way. This is a proof by induction and a very deeply argued point of philosophy. This, sadly, leaves a few things to just be taken for granted or forces a person to become a philosopher so they can more properly argue about them.
The negatives cancel out!
Such as if you have: 3 x 3
the negatives cancel out to be: 3 x 3
and both of those math problems equal 6
You can watch him write it out in this video between 3:10 and 3:20.
*Hope that helped!*
Such as if you have: 3 x 3
the negatives cancel out to be: 3 x 3
and both of those math problems equal 6
You can watch him write it out in this video between 3:10 and 3:20.
*Hope that helped!*
At 3:59, why doesn't 1 times 0 equal 0 ? Why is it just 0?
0 isn't negative, and it isn't positive either. It's a neutral number.
If you look at an ocean.
Above sea level
Sea level 
below sea level
So when you just say sea level it's like zero . You wouldn't say negative sea level or positive sea level.
Above sea level
Sea level 
below sea level
So when you just say sea level it's like zero . You wouldn't say negative sea level or positive sea level.
That is because 0 is a unique number that is the opposite of itself. In other words, 0 is just 0. And just like (1) will simplify to 1, so 0 will simplify to 0.
0 is not positive or negative, so +0 or 0 make no sense.
Anything times zero equals zero.
It's also a neutral number, like Danielle C said.
Anything times zero equals zero.
It's also a neutral number, like Danielle C said.
0 has no integer.
Think about a number line. Zero is the number that separates the positive numbers form the negatives, and as someone had said above, zero is a neutral number. In other words isn't a positive or a negative. (There is no 0 on the number line, it doesn't exist). Hope this helps!
Zero (0) is not a positive nor is it a negative. zero is just a really cool number
It is just 0 because anything times 0 is 0. And besides, there would be 1 0s or 0 1s.In addition, 0 isn't positive or negative. The most important thing is that 0 is nothing
Zero represents nothing, so how could there ever possibly be a negative nothing? That would not make sense.
0 can't be positive or negative so it can't be 0 or +0 😄
if u wish for your satisfaction, u can write it as +0 or 0 or 0 itself.
(1) Zero is the border between positive and negative numbers. Just like the border is not in either country it separates, so 0 is not positive or negative.
(2) The result of multiplying by 0 is 0 by definition. So according to that definition, it can't be positive or negative.
(2) The result of multiplying by 0 is 0 by definition. So according to that definition, it can't be positive or negative.
Zero is neither positive or negative. It is neutral, so you just write it like 0. ( like Danielle C )
But even though it is neutral, it is powerful! ( 1000 without any 0's would be 1 )
But even though it is neutral, it is powerful! ( 1000 without any 0's would be 1 )
Zero is niether NEGATIVE OR POSITIVE, so they don't want to go
+0
+0
If you look at an ocean.
Above sea level
Sea level 
below sea level
So when you just say sea level it's like zero . You wouldn't say negative sea level or positive sea level.
Above sea level
Sea level 
below sea level
So when you just say sea level it's like zero . You wouldn't say negative sea level or positive sea level.
if you can multiply negative can you divide them?
You can, and dividing negatives is actually very similar. Dividing a negative by a positive (and vice versa) gives you a negative. Dividing a negative with a negative gives you a positive. Hope this helps! :)
Yes. Remember, division is the same as multiplying by the reciprocal.
please watch from 0:10 to 5:32
Yes you can. Dividing and multiplying negatives are quite the same.
8/4=2
8/4=2
8/4=2
Hope I helped you!
8/4=2
8/4=2
8/4=2
Hope I helped you!
what happens if the equations is positive x positive x Negative
posted 11:20 ET USA
posted 11:20 ET USA
The product would be negative; Positive times negative is a negative, and another positive number won't change that:
5*4*2=40.
5*4*2=40.
The answer is negative.
really thanks i couldnt figure it out
why when we multiply or divide two negative number it is always positive?
The two negative signs cancel each other out to become positive. Or they cross to make a positive sign.
Think of it this way, suppose 2x4,this is saying minus x minus = plus and multiplication is just a simpler way of doing addition so you could say multiplication. That is why a neg. x neg.= pos. number
This may help. It explains why a negative times a negative is a positive. Hope it helps. https://www.khanacademy.org/math/arithmetic/absolutevalue/mult_div_negatives/v/whyanegativetimesanegativeisapositive
what helped me is to make a triangle and put two negative sign at bottom and a positive sign at the top and when I got two negative signs I would cover up the bottom negative signs and the positive sign at the top would show and Id know that it was a positive example 3x(9)=negative cause Id cover up a positive cause positive 3 and cover up a negative cause negative 9 and it would be a negative 27
No. If you know how to multiply and put in negative # signs, it is only too easy.
what hlped me make tirangl and put two
Do u know how hard this is
neg times neg pos_ pos times pos pos_ neg times pos neg_ pos times neg neg?
165,729,862
Yeah. I find it easy to think, if both numbers are on the same side of the number line, they come out positive, and viceversa.
Yup. You can think of it like this: when one is positive and the other one is negative (or viceversa), they are different, right? They "disagree", so the answer is immediately negative. When both of them are positive (or negative), they are identical, they "agree", therefore the answer is positive :) hope it helped ;)
how can I remember all of this? do you have a idea or any suggestions?
Two `like` signs become a positive, and two `unlike` signs become a negative.
Count the total number of "sticks" signs made of. If you got even, result will have an even too, same goes for odd.
what would 5 x 1 be? 1 x any other number is that number but i do not know if that works for negatives.
Yes, it works for negatives, too. 1 is a pretty cool number.
are you really talkin to me
5 x 1 IS 5, not 1
5x1 would be 1
thanks that really helped
If you did negative 1 or positive 1, how would you know what 1 it is? Because 1*1=1 . Would that 1 be a positive or negative 1?
That's why you have the () sign before a number and in your case if one of the ones is negative, you will see 1
Let's look at the four possibilities:
1 * 1 = 1. OR positive 1 * positive 1 = positive 1.
1 * 1 = 1, OR negative 1 * positive 1 = negative 1.
1 * 1 = 1, OR positive 1 * negative 1 = negative 1.
1 * 1 = 1, or negative 1 * negative 1 = positive 1.
1 * 1 = 1. OR positive 1 * positive 1 = positive 1.
1 * 1 = 1, OR negative 1 * positive 1 = negative 1.
1 * 1 = 1, OR positive 1 * negative 1 = negative 1.
1 * 1 = 1, or negative 1 * negative 1 = positive 1.
i am always getting confused with if you multiply a negative and a positive and a negative = what and a negative and negative or a positive and a positive = what ? same with division
This has always made it easier for me to remember 
positive = love
negative = hate
If you love love or hate hate, then you are positive.
If you love hate or hate love, then you are negative.
This also works for addition and subtraction for getting the signs correct.
Example: 6 + 4 =
The "plus negative" can be looked at as loving hate ("negative" or simply changing the sign to minus), so you are actually subtracting the 4 from the 6. The answer, of course, being 2.
I hope this helps.
positive = love
negative = hate
If you love love or hate hate, then you are positive.
If you love hate or hate love, then you are negative.
This also works for addition and subtraction for getting the signs correct.
Example: 6 + 4 =
The "plus negative" can be looked at as loving hate ("negative" or simply changing the sign to minus), so you are actually subtracting the 4 from the 6. The answer, of course, being 2.
I hope this helps.
a negative times a positive is a negative and the same the other way around, and a negative times a negative and a positive times a positive is a positive. so the negative times the positive will be a negative, and that times the other negative will be a positive.
I just thought that two lines like in 2 x3 and their are two lines in a positive sign like in +6 so that is my way of looking at it.
yes 2x3 epauls 6
epauls or equals
At 3:17, how is it that a negative times a negative is a positive?
Just an example that might be helpful:
If I say "Eat!" I am encouraging you to eat (positive)
But if I say "Do not eat!" I am saying the opposite (negative).
Now if I say "Do NOT not eat!", I am saying I don't want you to starve, so I am back to saying "Eat!" (positive).
If I say "Eat!" I am encouraging you to eat (positive)
But if I say "Do not eat!" I am saying the opposite (negative).
Now if I say "Do NOT not eat!", I am saying I don't want you to starve, so I am back to saying "Eat!" (positive).
What if it was a positive times a positive times a negative? Or a negative times a negative times a positive? Like 6 x 23 x 17.
If you have an odd number of negative numbers being multiplied, then the product will be negative. If you have an even number of negative numbers being multiplied, then the product will be positive.
e.g. 1 x 1 x 1 x 1 x 1 (There are five 1 is this problem, five is odd) = 1
e.g. 1 x 1 x 1 x 1 (There are four 1 is this problem, four is even) = 1
e.g. 1 x 1 x 1 x 1 x 1 (There are five 1 is this problem, five is odd) = 1
e.g. 1 x 1 x 1 x 1 (There are four 1 is this problem, four is even) = 1
do you have any practice on mutiplying positive and negative numbers ?
yes i am the top person on multiplication in my school with positive and negatives # (numbers) 9x5=45 or just do this 9+9+9+9+9=45 and for negatives is love and hate.
for example 9 x 5 =45 because u hate to love so it = hate
9 x 9 = 81 because u hate to hate so it = love
hate =  and love= +
for example 9 x 5 =45 because u hate to love so it = hate
9 x 9 = 81 because u hate to hate so it = love
hate =  and love= +
How come if it's negative times positive, it's negative, and if it's positive times negative, it's still negative? Or is it the same with the normal multiplication?
If it's negative times positive yes, it's negative but when it's positive times negative times positive it's negative too.(Does not matter which way just like it is in normal multiplication.Your right.)
so I don't get why negative + negative = a positive
Actually, it's negative x negative.
I don't really get it either, but that's how it works.
I don't really get it either, but that's how it works.
Negative + negative equals a negative, but yes, negative X negative = positive. This is because of what multiplying by a negative number represents. We learned negative numbers as "taking away" or owing something, in the context of adding and number lines. If you have 3 dollars, then you owe someone that much, or if you start with 4 apples, and have to give away 5 apples, you are one apple "short" or you "have 1 apples."
In the context of multiplication, we talk about how many total we have if we have 3 groups of 5 apples  that is 3x5=15 apples. Well, that doesn't quite work for negatives, unless we start to talk about owing again: we owe 3 people $5 each, so 3x(5)=15 we owe 15 dollars. But now, what about two negatives? There are "3" people to whom we owe 5 dollars... maybe that means three people owe us? So (3)x(5)=15 so we actually GET $15. Not terribly sensical, but maybe someone else can elaborate further?
In the context of multiplication, we talk about how many total we have if we have 3 groups of 5 apples  that is 3x5=15 apples. Well, that doesn't quite work for negatives, unless we start to talk about owing again: we owe 3 people $5 each, so 3x(5)=15 we owe 15 dollars. But now, what about two negatives? There are "3" people to whom we owe 5 dollars... maybe that means three people owe us? So (3)x(5)=15 so we actually GET $15. Not terribly sensical, but maybe someone else can elaborate further?
I'm having trouble remembering
+ x + = +
 x  = ?
I can never remembering what combinations equal what. Any story thingys that help you remember? I know the previous person said "Does my saying work; If a Bad thing happens to a bad person (x  x) its a good thing (answer would be a positive)?" But I need every other combination and the answers to it you know:
Negative times positive equals what?
Positive times negative equals what?
+ x + = +
 x  = ?
I can never remembering what combinations equal what. Any story thingys that help you remember? I know the previous person said "Does my saying work; If a Bad thing happens to a bad person (x  x) its a good thing (answer would be a positive)?" But I need every other combination and the answers to it you know:
Negative times positive equals what?
Positive times negative equals what?
Count up the number of negatives that are being multiplied or divided. If you have an even number of negatives, your answer will be positive. If you have an odd number of negatives, your answer will be negative.
The order in which they are multiplied does not matter.
The order in which they are multiplied does not matter.
hi everyone!! how can you add the neg times a pos
If you have a "neg times a pos" then it will be a negative. Calculate the number (which will be negative) then add as usual.
The way I remember it, is that among deer, one male deer has this whole group of female deer, and he's more powerful than them. And if another male deer tries to take over, they fight, and sometimes they both die. So the negative is like the male deer, and the positive is like a female deer. The female deer get along, so pos x pos = pos. If a male deer confronts a female deer, the female deer will back down, so neg x pos = neg. And if two male deer confront each other, they both die, so they cancel out: neg x neg = pos. I'm probably the only one who understands this, but I want to share it anyway.
Hi.Can anybody tell me how to use a timestamp?please.
Hi Abhimanyu!
Say you are referring to 2:15 in a video then all you have to do is type 2 : 1 5.
(Without the spaces in between the numbers☺).
I hope that helped!
Say you are referring to 2:15 in a video then all you have to do is type 2 : 1 5.
(Without the spaces in between the numbers☺).
I hope that helped!
So on the chart on the bottom it doesn't say what is a negative times a positive or is it the same as a positive times negative?
Yes. With multiplication, the order doesn't matter (the commutative property of multiplication), so a negative times a positive is the same thing as a positive times a negative.
A positive times a negative and a negative times a positive are both a negative.
why isnt zero a defined number????
zero is defined number, but deviding by zero isn't.
What do you mean by defined number?
At 2:39, could someone demonstrate how this works on the number line? Negative numbers to the left of zero, positive numbers to the right.
I can't do a video to show you, but I can explain it and if you draw it on a number line, you can see for yourself how it works.
The expression was 2 * 3.
Let me first explain how you would represent 2 * 3 on the number line.
2 means go left 2 postions. Start at zero and go left two postions and then go left two more postions and then go left two more positons. You are now at 6.
Ok, now lets do 2 * 3. Two is positive so it means go right two postions. The minus on the second number means opposite, So, start at 0 and go the opposite of right two postions and go opposite of right right more postions and go opposite of right two more positions. And again you are at 6.
Now lets do 2 * 3. The negative on the two means go right. The negative on the three means go opposite.
So start at zero. Go the opposite of right two positons and go the opposite or right two more postons and go the opposite of right two more postions. You are now at 6.
So 2*3 = 6 and you have shown it on a number line.
I hope that helps.
The expression was 2 * 3.
Let me first explain how you would represent 2 * 3 on the number line.
2 means go left 2 postions. Start at zero and go left two postions and then go left two more postions and then go left two more positons. You are now at 6.
Ok, now lets do 2 * 3. Two is positive so it means go right two postions. The minus on the second number means opposite, So, start at 0 and go the opposite of right two postions and go opposite of right right more postions and go opposite of right two more positions. And again you are at 6.
Now lets do 2 * 3. The negative on the two means go right. The negative on the three means go opposite.
So start at zero. Go the opposite of right two positons and go the opposite or right two more postons and go the opposite of right two more postions. You are now at 6.
So 2*3 = 6 and you have shown it on a number line.
I hope that helps.
So a negative times a negative is a positive?
Yep, thats right! Good job on figuring that out! :)
Yes, a negative times a negative is a positive
sal said 3*2 is 2 plus it self 3 times: 2 + 2 + 2.
how do you do 3 plus itself 2 times?
how do you do 3 plus itself 2 times?
You do 0  3  3
so if I understand this correctly  0 x 1 = 0 instead of 0? is there ever a case where 0 will be negative as opposed to positive? I'm thinking I understand that 0 is always 0 and never negative  am I right?
0 is neither a positive or a negative number. This is because numbers are classified as whether or not they are larger or smaller than 0. It would be like saying 0>0 or 0<0, which is not correct because 0=0. Just remember 0 as a kind of placeholder on a number line.
0 is a neutral number.
Thank you very much!
how do you do this? its confusing me and Im not exactly a math person but im not bad at it. Can anyone help me on this? IT IS VERY CONFUSING!
What u need help on cause I can help u??
I can help 2 k :>
It's not really confusing; you would multiply/divide the two numbers as you normally would and all you need to know is that (neg x pos = neg) (neg x neg = pos) (and of course pos x pos = pos)
example: 8 x 4 just get the answer which is 32 and then you can remember that (pos x neg = neg), so you get 32
hope this helps
example: 8 x 4 just get the answer which is 32 and then you can remember that (pos x neg = neg), so you get 32
hope this helps
But there is no video about multiplying 3 different numbers that are negative, but if there is tell me about it please kinda confused.
You can multiply two of the numbers and get the answer. Multiply that answer by the third number.
Here's an example: Multiply (3)(4)(2)
First multiply 3 by 4 = 12
Then multiply the answer 12 by 2 = 24
So the answer is 24.
Hope this helps.
Here's an example: Multiply (3)(4)(2)
First multiply 3 by 4 = 12
Then multiply the answer 12 by 2 = 24
So the answer is 24.
Hope this helps.
What about 10 times 4 times 2 do all of them cancel out?
No, if you're multiplying an odd number of negative values then your final answer will be negative.
Nathan is right and another way of thinking about it is this: so let's say 10 x 4 x 2
10 x 4 would be +40. then you multiply +40 by 2 and you'll get 80
multiplying three (or any odd number of) negative numbers will always have a negative answer
10 x 4 would be +40. then you multiply +40 by 2 and you'll get 80
multiplying three (or any odd number of) negative numbers will always have a negative answer
Would brackets have any effect on these equations or no?
Thanks!
Thanks!
I don't think it would, most of the problems he does here are singlestep (just a * b), instead of multi steps where you use the order of operations(bedmas)(a+c*b/de), since brackets only real purpose are to tell you to do this first, before you do anything else, a pair of brackets wouldn't change anything.
Hope this helped
Hope this helped
why is it that a negative times a positive and a positive times a negative?
watch the 2nd video then you will know
why is it so tricky?
Well, I guess because it has negative numbers involved. To make it easy, all you need to remember is that positive x positive = positive, negative x negative = positive and positive x negative = negative. After you memorise that, it will hopefully become easier :)
At 0:32 he starts telling us about positives and negatives. Does my saying work; If a Bad thing happens to a bad person (x  x) its a good thing (answer would be a positive)?
Mathematically, we would get a neutral or positive. We wold probably represent it more as an addition problem in math, but the abstract concept of a negative negative will always give a positive still stands in your saying. :)
It's kind of saying like : I will not not do something...
Interesting Question. :)
Sylvia.
It's kind of saying like : I will not not do something...
Interesting Question. :)
Sylvia.
Thank you for helping me out! :)
i did and i still dont get it
At 1:12 , your saying that  X + = ?
while  X  = +.
I don't understand that.
Can you please explain it?
while  X  = +.
I don't understand that.
Can you please explain it?
Why would you cancel out when you can act like it is not even there at all and how can 1x0=0 I thought you said that a neg.+pos.=neg so shouldn't it be a neg. instead of a pos. ?
Anytime you multiply or divide by zero it is always zero. 0x1=0 and 0x1 is still 0.
Yes,that is true u could just act like its not even their but teachers perfur you to cancel out
dis is confusing people i knew how to do it but know i don't Llf..............
So I was wondering, can you or can you not use a number line?...
if a question ask you to use a number line or if it dosent but you can use it to help you
This really helped! Thanks!
i mean why does 2 Negatives = a positive?
If you multiplied 1 times 1 would would be the answer?
makes a lot of sense
At 0:44 Sal says that 2 * 3 = 6, or 2+2+2 couldn't we write this as 2+(2)+(2)? Thanks!
So, neg. x neg. and pos. x pos. = pos., while neg. x pos. and pos. x neg. = neg.?
Are you sure its right i got a diffreant answer Just Kiddin
why doesn't 1 times 0 equal 0 ? Why is it just 0?
There is no such thing as "0". It is just known as 0.
Anything multiplied by 0 is 0.
Anything multiplied by 0 is 0.
If I had a negetive times a positive what will happen ?
A negative times a positive will make the product (answer) a negative. I can't explain it as good as Sal but there is a video by him on what happens when two negatives multiply. The video can answer your question better than I can. Here is the URL code for the video: https://www.khanacademy.org/math/arithmetic/absolutevalue/mult_div_negatives/v/whyanegativetimesanegativeisapositive
at 1:43 i dont understand:( HELP!!!!!!!!!!!!!!
three groups of 2. what do you get?
6
6
What does it mean when something is UNDEFINED ?
=(
=(
It means to not defined or made clear: the job has remained undefined.
Exactly what it means.
Im new and i was wondering how to make a video and put it up??
I'm not sure that's possible..
In general, we're just students here...
the people making the videos are employed to do so..
In general, we're just students here...
the people making the videos are employed to do so..
I Don't think you can
Can someone demonstrate how this works on the number line?
You can think of it this way: If someone you like asks you to dance, that's good (positive). If someone you like doesn't ask you to dance, that's bad (negative). If someone you don't like asks you to dance, that's bad. If someone you don't like doesn't ask you to dance, that's good.
i always remember negative x's negative = positive and positive x's positive = positive
Negative x's positive = negative
Same for division
Negative x's positive = negative
Same for division
there is a rule for positive and negitive numbers which is " if the signs are the same the answer is positive but if the signs are opposite the answer is negitive" but i have a multiplication question which is ' 8 x 0 = 0 ' but that then should be a negitive number acording to the rule can someone please explain why this is
thanks
thanks
zero is just zero, it can't be negative or positive.
zero is just zero, it can't be negative or positive.
at 5:17 do you multiply positive numbers the same way you multiply regular numbers..? if so do the positive numbers cancel out and the awnser become negative..?
ok but what I don't understand is how negative x negative =positive but positive x positive =positive how does that work..? shouldn't it be positive x positive =negative...?
A positive x negative will make a negative: 2 x 3 = 6
A positive x positive will make a positive: 2 x 3 = 6
A negative x negative will make a positive: 2 x 3 = 6
A positive x positive will make a positive: 2 x 3 = 6
A negative x negative will make a positive: 2 x 3 = 6
cna yoy post word problerms on the samr?
at 2:39 can some please exsplain to me haw the number line gose ? negative # to the left zero,positive # to right
math is fun, when ur programming games... (my opinion here) :)
I don't get the exercise because I always have to like, do for example: 1 x 1 and It always changes weirdly. If someone could tell me what I have to do, It would be greatly appreciated. Thank you.
How come the product and quotient of two negative numbers are positive while you have to copy the sign in addition and subtraction?
is there an excersise for this lesson?
at 0:10 I dint under stand any thing
sumtimes i cant find the lessons i need and i keep trying but its just not there
hav any tips?
hav any tips?
why is there no practicing the consept? o.o
Why do two negatives create a positive
because it is always opposite
Why do to negatives make a positive when multiplying but not when adding because multiplying is just repeated addition?
You've got that statement sort of correct. Multiplying isn't exactly repeated addition. Negatives make a positive when multiplying because the negatives cancel each other out and leave you with just the numbers. Negatives stay negatives when adding because the negative signs don't cancel out here. You keep the sign and add the numbers.
Is 2 x 2 =4;yes or no?
Yes, it is. 2 x 2 is 4 since they are both negative. Negative times a negative is always a positive.
What if you multiply more than 2 numbers? Like 2*3*4? Or 5*3*7? Or 6*9*8? How would you work that out?
Left to right, so multiply the first two together, and then multiply that answer with the third number.
at 7 secins it stop`t at first
So if it is one negative number, multiplying with another positive number is that positive? or negative? I don't understand which one.
No, multiplying numbers with different signs always yields negative. The same signs is always positive.
1 x 1 = 1
1 x 1 = 1
1 x 1 = 1
1 x 1 = 1
1 x 1 = 1
1 x 1 = 1
1 x 1 = 1
1 x 1 = 1
so will a neg.+ neg.+ pos. will thae awnser be a pos. or a neg.
If you're adding them:
(negative number)+(negative number)+(positive number) = ?
then the answer can be either positive or negative depending on the particular numbers. If you are multiplying:
(negative number) x (negative number) x (positive number) = (positive number)
then the answer will always be a positive number.
(negative number)+(negative number)+(positive number) = ?
then the answer can be either positive or negative depending on the particular numbers. If you are multiplying:
(negative number) x (negative number) x (positive number) = (positive number)
then the answer will always be a positive number.
How would you multiply 3 numbers? Ex. (1/2)X(1/2)X(1/2)=?
Would it equal +1/8 or 1/8?
Would it equal +1/8 or 1/8?
The product of 3 negatives would be negative.
If you have an even number of negative factors it's positive.
If you have an odd number of negative factors it's negative.
If you have an even number of negative factors it's positive.
If you have an odd number of negative factors it's negative.
A negative number multiplied by a negative number is a positive number.
(1/2)X(1/2) = (+1/4)
Now do (+1/4) x (1/2)
(1/2)X(1/2) = (+1/4)
Now do (+1/4) x (1/2)
Why are ± used and how?
It is used to change 7 to 7 or vise versa It is used to change a positive to a negative or vise versa
this stupid comper aintworkin
this video really helped me
but I have a question when you multiply a negative and a positive do you get a negative
but I have a question when you multiply a negative and a positive do you get a negative
yes correct. the negative cancels out the positive so its a negative number.
How to model (4)(4) using counters?
I think there should be a video bout it.
I think there should be a video bout it.
where to type it?
Does 2 x 3=2 x 3
Yes, I think its just an extension of the communitive property.
I am so lost....
in simpilar words can somebody explain the formula?
(if that makes ANY SINCE)
in simpilar words can somebody explain the formula?
(if that makes ANY SINCE)
Anything times a positive is a positive. But if a negative times a positive is going to equal a negative. The negative is always dominate... GET IT NOW :)
I don't get how 1 times 1 is +1
the negatives cancel each other out which gives you a positive.
at 2:27 it basically sums it up, negative times negative equals positive, and negative times negative times equals positive (same signs equal positive, different signs equal negative)
I really liked how you explained that to me and other users! :)
nice this helped me aloy
i thought this video was really helpful cuz in the beginning of the year i was not so good at this stuff
Could you be more specific and make a video just on dividing negative numbers? I could only find one in the search with multiplying. Thanks!
When Sal does 1x1=1 I don't get 1 I get 2
Thank alt but no i didn't add
Think of it this way, 1*1=1 right? Now remember the rule that negative and a negative make a positive? It works the same way here: 1*1=1. You might have gotten 2 by adding them, so maybe that's your mistake.
why is that 2 negative a positive?
how does Negative Times a Negative works on the number line?
a negative number times a negative number would equal a positive; so on the number line you would mark it as a positive number
what is 0.5147 times any number would be ?
People I need help with this question: Expand the following 3(5+4)2(31)= This is the way I would do it but I think it is incorrect: 3x5= 15 3x4= 12 add the two results together: 27
Then 2(31) 2x3= 6 2x1= 2 subtract the two results= 8 now I have 27 and 8 here is where I get stuck, is the answer 19? Need some help this question is part of a assignment which I need to hand in by 15/10/2012 after two days. If someone can point which videos or section I need to go to would be helpful. Thanks
Then 2(31) 2x3= 6 2x1= 2 subtract the two results= 8 now I have 27 and 8 here is where I get stuck, is the answer 19? Need some help this question is part of a assignment which I need to hand in by 15/10/2012 after two days. If someone can point which videos or section I need to go to would be helpful. Thanks
Why is it that when you multiply two negative numbers, they cancel each other out?
I think this is easier to understand intuitively using division first. Suppose you have ($8) in your bank account and you want to divide it equally into groups of ($2). You would have ($2)+($2)+($2)+($2) = ($8). That is, there are four equal groups. So a negative divided by a negative is a positive (8/2 = 4).
Now let's consider multiplying (3)x(2). Draw out a number line and put a dot at 0. (3)x(2) tells you that you add 3 two times. So from zero you go to the left three places to get to 3 (you've added 3 once), then left another three places to get to 6 (you've added 3 twice) so the answer is (3)x(2) = (6).
What if that 2 was negative (i.e. (3)x(2) = ?)? Then you would add 3 to itself two times _in the opposite direction_. So on the number line we start at zero, and instead of moving left, we move right 3 places to get to +3 (3 has been added 1 times), then we move another 3 places to the right (3 has been added 2 times total) to get to +6. That is, (3)x(2) = 6, and a negative multiplied by a negative is a positive (the negatives "cancel each other out").
Does that make sense?
Now let's consider multiplying (3)x(2). Draw out a number line and put a dot at 0. (3)x(2) tells you that you add 3 two times. So from zero you go to the left three places to get to 3 (you've added 3 once), then left another three places to get to 6 (you've added 3 twice) so the answer is (3)x(2) = (6).
What if that 2 was negative (i.e. (3)x(2) = ?)? Then you would add 3 to itself two times _in the opposite direction_. So on the number line we start at zero, and instead of moving left, we move right 3 places to get to +3 (3 has been added 1 times), then we move another 3 places to the right (3 has been added 2 times total) to get to +6. That is, (3)x(2) = 6, and a negative multiplied by a negative is a positive (the negatives "cancel each other out").
Does that make sense?
6:01 Is it the same with multiplying a negative number with a four digit poositive number?
does it have the same rule as as if you add and subtract negative numbers where you can change it like this: If you take 4 + 5 = 1 but adding a negative is the same thing as subtracting a positive so 4  5 = 1: can you do that with multiplying?
No not really. But you can change 4x5=20 to (5)4=20.
is it posable to put exponents on negitve numbers
Yes, negative numbers can be raised to both positive and negative powers.
this is too easy . . . wheres the harder stuff?
you can search up what you want to learn in the search bar that says "search for a video or topic"
how do you get a positive times a negative = a negative
take 2x 4 for example.
2x4= 2+2+2+2
2+2+2+2= 8
Look to the video "Adding Negative Numbers" if my explanation made no sense.
2x4= 2+2+2+2
2+2+2+2= 8
Look to the video "Adding Negative Numbers" if my explanation made no sense.
at 2:30 how many times can it go in to it
i dont get negative numbers can someone plese help i cant get this
Can somebody help me?
What would you like help with?
i thought the when the neg is bigger its alway a neg
^^ yay positive and negative ! hazahhhh
Report a mistake in the video
Example:
At 2:33, Sal said "single bonds" but meant "covalent bonds."
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