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.
if you do 7+9 it means you are adding 9
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!
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.
well you might use it to calculate the amount of interest you get in your bank account?
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!*
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.
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.
(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.
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 (0) is not a positive nor is it a negative. zero is just a really cool number
Zero represents nothing, so how could there ever possibly be a negative nothing? That would not make sense.
if u wish for your satisfaction, u can write it as +0 or 0 or 0 itself.
0 can't be positive or negative so it can't be 0 or +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 is niether NEGATIVE OR POSITIVE, so they don't want to go
+0
+0
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 )
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 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!
please watch from 0:10 to 5:32
Yes. Remember, division is the same as multiplying by the reciprocal.
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 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.
thanks that really helped
are you really talkin to me
5x1 would be 1
5 x 1 IS 5, not 1
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.
neg times neg pos_ pos times pos pos_ neg times pos neg_ pos times neg neg?
165,729,862
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 ;)
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.
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.
Do u know how hard this is
what hlped me make tirangl and put two
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
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.
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.
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
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?
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.
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
why is it that a negative times a positive and a positive times a negative?
watch the 2nd video then you will know
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
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! :)
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.
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= +
why isnt zero a defined number????
zero is defined number, but deviding by zero isn't.
What do you mean by defined number?
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?
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
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 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
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
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.
Thank you very much!
0 is a neutral number.
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.
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.
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).
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.
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 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 :)
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
why is there so many videos and not enough practices am i going cazy or is there more practices with each video?
You can repeat the review the practices anytime and you'll generally spend more time with them than the videos as you go further into the future.
makes a lot of sense
Never Mind I figured it out :)
i mean why does 2 Negatives = a positive?
neg x neg = pos
pos x neg = neg
pos x pos = pos
thats how it works.
live with it
pos x neg = neg
pos x pos = pos
thats how it works.
live with it
thankyou so much
School standards have dropped. I am already past this in 6th.
yeah. I remember learning this in 6th.
Why neg times neg equal positive
i have no idea, even though it *is* true.
but, here is a disclaimer
_people say multiplication is repeated addition. if so, then look at this:
5*3
5+5+5
15_
i have no idea how it is positive, but we just stick to that.
but, here is a disclaimer
_people say multiplication is repeated addition. if so, then look at this:
5*3
5+5+5
15_
i have no idea how it is positive, but we just stick to that.
This Is All Confusing To Me Just Integers Help Its Like Not The Same As We Learn IN School Comment Please......!
what is that whit box thing that popped up in 5:05 ?
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
at 3:04 why do we use negative for positive.
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.
20 boys are in a class with 28 girls. What percentage are the girls?
hi, if you multiply a  # x  # =  # but if you multiply a  # x  # x  # = + # right?
Oh wow. You aiming to be a mathematician?? Tip: instead of writing # write 'n' it's a common variable, or letter used to represent an number of unknown value. :)
Okay: onto your question: if you muliptly a * b = c, but if you muliptly  x * y * z = * u, right? _Please remember that these letters are the same thing as writing #_
I'm afraid you've gotten it mixed up... a negative number * negative number = positive number.
A positive number * negative number = negative number.
So: if you have, let's say 5 * 5, you're going to get an answer of *positive* 25.
If you have 5 * 5 * 5 you're going to get an answer of *negative* 125.
So, (using your symbols): a # * # = +#
and a # * # * # = #
Remember: if you have an even number of negative numbers (2, 4, 6, 10..100 etc) you will get a positive number
If you have an odd number of negative number (3, 5, 7, 111) you will get a negative number.
Those rules will be very important to know when you get into exponents!
Hope this helped,
Sylvia.
Okay: onto your question: if you muliptly a * b = c, but if you muliptly  x * y * z = * u, right? _Please remember that these letters are the same thing as writing #_
I'm afraid you've gotten it mixed up... a negative number * negative number = positive number.
A positive number * negative number = negative number.
So: if you have, let's say 5 * 5, you're going to get an answer of *positive* 25.
If you have 5 * 5 * 5 you're going to get an answer of *negative* 125.
So, (using your symbols): a # * # = +#
and a # * # * # = #
Remember: if you have an even number of negative numbers (2, 4, 6, 10..100 etc) you will get a positive number
If you have an odd number of negative number (3, 5, 7, 111) you will get a negative number.
Those rules will be very important to know when you get into exponents!
Hope this helped,
Sylvia.
thanks you helped me alot
dis is confusing people i knew how to do it but know i don't Llf..............
Why when you multiply negative #s is the answer positive?
Ok. I'll try and make this as clear as possible. During the video Sal keeps saying two negatives always make a positive. But when you multiply a negative by a negative wouldn't you either get the number you are multiplying or 0?
Say I'm multiplying 6 by 7. I would go from 6 to zero. Then onward to positive 6. But then the current answer would be positive so wouldn't I subtract 6 the next time?
Say I'm multiplying 6 by 7. I would go from 6 to zero. Then onward to positive 6. But then the current answer would be positive so wouldn't I subtract 6 the next time?
But you aren't adding and subtracting here, you are multiplying.
Adding 2 negatives will always give you a negative answer
Multiplying 2 negatives will always give you a positive though.
Another way of saying negative is "the opposite of".
So every time you multiply by a negative the sign will flip.
If you have 1, 3, 5, . . . negative factors in a string of multiplications, the final answer is negative.
If you have 2, 4, 6, ... negative factors the final answer will be positive.
(2)(3) = +6 or just 6
(2)(3)(1) = 6
Using arrows on a number line helps when you are adding but not when you are multiplying.
I hope this helps.
Adding 2 negatives will always give you a negative answer
Multiplying 2 negatives will always give you a positive though.
Another way of saying negative is "the opposite of".
So every time you multiply by a negative the sign will flip.
If you have 1, 3, 5, . . . negative factors in a string of multiplications, the final answer is negative.
If you have 2, 4, 6, ... negative factors the final answer will be positive.
(2)(3) = +6 or just 6
(2)(3)(1) = 6
Using arrows on a number line helps when you are adding but not when you are multiplying.
I hope this helps.
When feuhr ffgue rugfuefgu fhreiynfuyernfuhre
i dont get negative numbers can someone plese help i cant get this
How can you remember if a pos x neg = ? or neg x neg =? are there any ways to remeber like P.E.M.D.A.S
This is my way of remembering it:
Both sides have the same sign? Positive Number.
Both sides have a different sign? Negative Number.
Both sides have the same sign? Positive Number.
Both sides have a different sign? Negative Number.
Is that the same for multiply,divide,addition,subtraction?
This confused me before too but over time with plenty of practice it becomes second nature, same with PEMDAS. I don't think there is much of a trick to remember it.
at 2:39 can some please exsplain to me haw the number line gose ? negative # to the left zero,positive # to right
Is there a place to practice Questions on a specific topic, like word probelms? If so, where is it?
a way to think of a negative times a negative is that negative sign plus negative sign the two negative lines make a positive sign or:
 +  = +
 +  = +
So basically if you take 2x3=6 and if you make the same equation a negative ,you will get the same answer,6?
Do you mean (2x3)? This would equal 6.
Or do you mean (2)x(3)? That would equal 6.
Or do you mean (2)x(3)? That would equal 6.
why is there no practicing the consept? o.o
i thought this video was really helpful cuz in the beginning of the year i was not so good at this stuff
Hi, guys. I'm new on khan academy and could you tell me where can i find some exercises, please?
You can go to to *LEARN* at the top of the page and click on the *Knowledge Map* link and it will take you to the map of exercises.
at 7 secins it stop`t at first
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"
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.
I don't get how 1 times 1 is +1
the negatives cancel each other out which gives you a positive.
i used to think that those were hard they kinda easy if u listien and ask ouestions
How many multiplications of positive + negative integers are there with an answer of 6 ?
one negative and one positive example 3x(2)
how do u make absinth
How do I practice this activity?
is it posable to put exponents on negitve numbers
Yes, negative numbers can be raised to both positive and negative powers.
Can this get more complicated?
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 :)
its not realy that hard to me somtimes like neg. times a poz = neg. or poz times a poz =poz or a neg times a neg =poz examples 7x1=7 7x1=7 7x1=7 i think thhats how it gose
What is the difference (not meaning subtraction) between – (m3n) and (mn)3 ? (The "3" is an exponent.) That is, what happens when a negative sign is inside verses outside of the parentheses?
if i had 3 + 5 would it be neg or pos and would i add or sub?
Here's a quick way to remember addition with negative numbers:
If the two numbers have the same sign, you add them and keep the sign. If they have different signs, you subtract them and keep the sign of the larger number. Thus,
 3 + 5 = 8
3 + 5 = 8
 3 + 5 = 2
3 + 5 = 2
If the two numbers have the same sign, you add them and keep the sign. If they have different signs, you subtract them and keep the sign of the larger number. Thus,
 3 + 5 = 8
3 + 5 = 8
 3 + 5 = 2
3 + 5 = 2
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
how do u know these ruls
what about the laws of pemdas?
negative numbers are just like positive numbers when it comes to PEMDAS.
How do you kown if it is postive or negtive number
Same sign add and keep different sign subtract keep the sign of the highest number than they be exact. Example: 3+4=1 highest number is 4 so the answer is a positive.
at 0:35 he starts talking about multiplying negatives and positives. I don't get it, why is a positive times a negative always negative?
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.
Yeah at 2:39 it doesnt really make sense on the number line
What does it mean when something is UNDEFINED ?
=(
=(
Exactly what it means.
It means to not defined or made clear: the job has remained undefined.
i thought the when the neg is bigger its alway a neg
what program are you useing please tell me
why is negative times a negative positive ?
my friend taught me if you hate (negative) to hate (negative) then you love (positive).
because both the negatives cancel each other out and make the number positives Example 2 x 3=6 because both numbers have a negative and cancel each other out, so both become positive. 2 x 3= 6 because there is only one negative
how do negatives times negatives cancel out?
It might help to think of multiplying by negatives to be like flipping something over. If you flip something over twice (multiply 2 negatives) it will be where it was at the start (positive)
Does sal have a video explaining why a negative x a negative is possible?
dues it work the same for + ?
No, the final sign is dependent upon which number's absolute value (distance from zero) is greater. So, if both are negative, you'll go farther negative.
You no how u did the problem and =0 doesn't that still make it 0 are just zero
Does 2 x 3=2 x 3
Yes, I think its just an extension of the communitive property.
so the neg and the neg cansasle out
thank you for the help
Yes, two negatives equal a positive answer. But if there is ever a two negatives and a positive then the answer will be negative.
Hope this helped!
Hope this helped!
How come the product and quotient of two negative numbers are positive while you have to copy the sign in addition and subtraction?
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.
Is there a video on that with decimals involved ?😄😄😄
The rules are exactly the same. With multiplying and/or dividing with negative numbers here is how you do it:
Step 1: Do the math as though the negative signs were not there.
Step 2: Count up the number of negative signs. If there is an even number of negative signs, the answer is positive. If there is an odd number of negative signs, the answer is negative.
Step 1: Do the math as though the negative signs were not there.
Step 2: Count up the number of negative signs. If there is an even number of negative signs, the answer is positive. If there is an odd number of negative signs, the answer is negative.
Would (3)*(3)*(3) equal a positive or negative number?
Actually, it would equal 27 because (3)*(3)= +9, and +9* (3) would equal 27.
It would equal +27 or positive 27
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.
What is zero really some people say negative other people say neutral please like my question and answer it! :)
Zero is neither positive nor negative
Is it neutral?
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.
Report a mistake in the video
Example:
At 2:33, Sal said "single bonds" but meant "covalent bonds."
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