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## Multiplying and dividing negative numbers

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## Multiplying positive and negative numbers

Basics of multiplication with negative numbers
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## Multiplying positive and negative numbers

Discussion and questions for this video
Can anyone think of any ways to connect multiplying two negative numbers with a real-world application? or how to actually SUPPORT WWHHYY two negatives produce a positive with multiplying/dividing?
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 re-allocate 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. 4 Votes Comment At 3:59, why doesn't -1 times 0 equal -0 ? Why is it just 0? 8 Votes 2 Comments 0 isn't negative, and it isn't positive either. It's a neutral number. 15 Votes Comment if you can multiply negative can you divide them? 6 Votes Comment 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! :) 7 Votes Comment what happens if the equations is positive x positive x Negative posted 11:20 ET USA 7 Votes Comment The product would be negative; Positive times negative is a negative, and another positive number won't change that: 5*4*-2=-40. 3 Votes Comment why when we multiply or divide two negative number it is always positive? 5 Votes 2 Comments The two negative signs cancel each other out to become positive. Or they cross to make a positive sign. 4 Votes Comment 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 4 Votes Comment No. If you know how to multiply and put in negative # signs, it is only too easy. 1 Vote Comment neg times neg pos_ pos times pos pos_ neg times pos neg_ pos times neg neg? 3 Votes Comment 165,729,862 1 Vote Comment how can I remember all of this? do you have a idea or any suggestions? 2 Votes Comment Two like signs become a positive, and two unlike signs become a negative. 3 Votes 2 Comments what would -5 x 1 be? 1 x any other number is that number but i do not know if that works for negatives. 1 Vote 2 Comments Yes, it works for negatives, too. 1 is a pretty cool number. 5 Votes 1 Comment 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? 2 Votes Comment 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 1 Vote Comment 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 2 Votes Comment 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. 1 Vote Comment I just thought that two lines like in -2 x-3 and their are two lines in a positive sign like in +6 so that is my way of looking at it. 3 Votes 1 Comment yes -2x-3 epauls -6 0 Votes Comment At 3:17, how is it that a negative times a negative is a positive? 1 Vote Comment 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). 2 Votes Comment 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. 1 Vote Comment 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 2 Votes Comment do you have any practice on mutiplying positive and negative numbers ? 1 Vote Comment 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= + 2 Votes Comment 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? 0 Votes Comment 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.) 4 Votes 2 Comments so I don't get why negative + negative = a positive 2 Votes 1 Comment Actually, it's negative x negative. I don't really get it either, but that's how it works. 1 Vote Comment 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? 1 Vote Comment 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. 2 Votes Comment hi everyone!! how can you add the neg times a pos 1 Vote Comment 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. 2 Votes Comment Hi.Can anybody tell me how to use a timestamp?please. 1 Vote Comment 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! 2 Votes Comment 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? 1 Vote Comment 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. 2 Votes 1 Comment why isnt zero a defined number???? 1 Vote Comment zero is defined number, but deviding by zero isn't. 2 Votes 1 Comment 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. 2 Votes Comment 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. 1 Vote Comment So a negative times a negative is a positive? 0 Votes Comment Yep, thats right! Good job on figuring that out! :) 4 Votes Comment sal said 3*-2 is -2 plus it self 3 times: -2 + -2 + -2. how do you do 3 plus itself -2 times? 1 Vote Comment You do 0 - 3 - 3 2 Votes Comment 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? 1 Vote Comment 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. 2 Votes Comment 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! 1 Vote Comment What u need help on cause I can help u?? 2 Votes 3 Comments But there is no video about multiplying 3 different numbers that are negative, but if there is tell me about it please kinda confused. 1 Vote Comment 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. 2 Votes Comment What about -10 times -4 times -2 do all of them cancel out? 1 Vote Comment No, if you're multiplying an odd number of negative values then your final answer will be negative. 2 Votes 2 Comments Would brackets have any effect on these equations or no? Thanks! 1 Vote Comment I don't think it would, most of the problems he does here are single-step (just a * b), instead of multi steps where you use the order of operations(bedmas)(a+c*b/d-e), 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 2 Votes Comment why is it that a negative times a positive and a positive times a negative? 2 Votes Comment watch the 2nd video then you will know 0 Votes Comment why is it so tricky? 1 Vote Comment 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 :) 2 Votes Comment 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)? 1 Vote Comment 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. 2 Votes Comment i did and i still dont get it 1 Vote Comment At 1:12 , your saying that - X + = -? while - X - = +. I don't understand that. Can you please explain it? 1 Vote Comment 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. ? 1 Vote Comment Anytime you multiply or divide by zero it is always zero. 0x1=0 and 0x-1 is still 0. 1 Vote Comment dis is confusing people i knew how to do it but know i don't Llf.............. 1 Vote Comment So I was wondering, can you or can you not use a number line?... 1 Vote Comment if a question ask you to use a number line or if it dosent but you can use it to help you 1 Vote Comment This really helped! Thanks! 1 Vote Comment i mean why does 2 Negatives = a positive? 1 Vote Comment If you multiplied -1 times 1 would would be the answer? 1 Vote Comment -1 your welcome 1 Vote Comment makes a lot of sense 1 Vote Comment At 0:44 Sal says that -2 * 3 = -6, or -2+-2+-2 couldn't we write this as -2+(-2)+(-2)? Thanks! 1 Vote Comment So, neg. x neg. and pos. x pos. = pos., while neg. x pos. and pos. x neg. = neg.? 1 Vote Comment Are you sure its right i got a diffreant answer Just Kiddin 1 Vote Comment why doesn't -1 times 0 equal -0 ? Why is it just 0? 1 Vote Comment There is no such thing as "-0". It is just known as 0. Anything multiplied by 0 is 0. 1 Vote Comment If I had a negetive times a positive what will happen ? 1 Vote Comment 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/absolute-value/mult_div_negatives/v/why-a-negative-times-a-negative-is-a-positive 1 Vote Comment at 1:43 i dont understand:( HELP!!!!!!!!!!!!!! 1 Vote Comment three groups of -2. what do you get? -6 1 Vote Comment What does it mean when something is UNDEFINED ? =( 1 Vote Comment It means to not defined or made clear: the job has remained undefined. 1 Vote Comment Im new and i was wondering how to make a video and put it up?? 0 Votes Comment I'm not sure that's possible.. In general, we're just students here... the people making the videos are employed to do so.. 3 Votes 1 Comment Can someone demonstrate how this works on the number line? 1 Vote Comment 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. 1 Vote Comment i always remember negative x's negative = positive and positive x's positive = positive Negative x's positive = negative Same for division 1 Vote Comment 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 1 Vote Comment zero is just zero, it can't be negative or positive. 1 Vote Comment 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..? 1 Vote Comment 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...? 1 Vote Comment cna yoy post word problerms on the samr? 1 Vote Comment at 2:39 can some please exsplain to me haw the number line gose ? negative # to the left zero,positive # to right 1 Vote Comment math is fun, when ur programming games... (my opinion here) :) 1 Vote 1 Comment 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. 1 Vote Comment How come the product and quotient of two negative numbers are positive while you have to copy the sign in addition and subtraction? 1 Vote Comment is there an excersise for this lesson? 1 Vote Comment at 0:10 I dint under stand any thing 1 Vote Comment sumtimes i cant find the lessons i need and i keep trying but its just not there hav any tips? 1 Vote Comment why is there no practicing the consept? o.o 1 Vote Comment Why do two negatives create a positive 1 Vote Comment because it is always opposite 1 Vote Comment Why do to negatives make a positive when multiplying but not when adding because multiplying is just repeated addition? 1 Vote Comment 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. 1 Vote Comment Is -2 x -2 =4;yes or no? 1 Vote Comment Yes, it is. -2 x -2 is 4 since they are both negative. Negative times a negative is always a positive. 1 Vote Comment 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? 1 Vote Comment Left to right, so multiply the first two together, and then multiply that answer with the third number. 1 Vote Comment at 7 secins it stop`t at first 1 Vote Comment So if it is one negative number, multiplying with another positive number is that positive? or negative? I don't understand which one. 1 Vote Comment 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 Vote Comment so will a neg.+ neg.+ pos. will thae awnser be a pos. or a neg. 1 Vote Comment 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. 1 Vote 2 Comments How would you multiply 3 numbers? Ex. (-1/2)X(-1/2)X(-1/2)=? Would it equal +1/8 or -1/8? 1 Vote Comment 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. 1 Vote Comment Why are ± used and how? 1 Vote Comment It is used to change 7 to -7 or vise versa It is used to change a positive to a negative or vise versa 1 Vote 1 Comment this stupid comper aintworkin 1 Vote Comment this video really helped me but I have a question when you multiply a negative and a positive do you get a negative 1 Vote Comment yes correct. the negative cancels out the positive so its a negative number. 1 Vote Comment How to model (-4)(-4) using counters? I think there should be a video bout it. 1 Vote Comment where to type it? 1 Vote Comment Does -2 x 3=2 x -3 1 Vote Comment Yes, I think its just an extension of the communitive property. 1 Vote Comment I am so lost.... in simpilar words can somebody explain the formula? (if that makes ANY SINCE) 1 Vote Comment 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 :) 1 Vote 3 Comments I don't get how -1 times -1 is +1 1 Vote Comment the negatives cancel each other out which gives you a positive. 1 Vote 1 Comment 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) 1 Vote Comment I really liked how you explained that to me and other users! :) 1 Vote Comment nice this helped me aloy 1 Vote Comment i thought this video was really helpful cuz in the beginning of the year i was not so good at this stuff 1 Vote Comment 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! 1 Vote Comment When Sal does -1x-1=1 I don't get 1 I get -2 1 Vote Comment Thank alt but no i didn't add 1 Vote Comment why is that 2 negative a positive? 1 Vote Comment how does Negative Times a Negative works on the number line? 1 Vote Comment a negative number times a negative number would equal a positive; so on the number line you would mark it as a positive number 1 Vote Comment what is 0.5147 times any number would be ? 1 Vote Comment People I need help with this question: Expand the following 3(5+4)-2(3-1)= 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(3-1) -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 1 Vote Comment Why is it that when you multiply two negative numbers, they cancel each other out? 1 Vote Comment 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?
1 Vote
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6:01 Is it the same with multiplying a negative number with a four digit poositive number?
1 Vote
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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?
1 Vote
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No not really. But you can change 4x-5=-20 to (-5)4=20.
1 Vote
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is it posable to put exponents on negitve numbers
1 Vote
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Yes, negative numbers can be raised to both positive and negative powers.
1 Vote
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this is too easy . . . wheres the harder stuff?
1 Vote
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you can search up what you want to learn in the search bar that says "search for a video or topic"
1 Vote
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how do you get a positive times a negative = a negative
1 Vote
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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.
1 Vote
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at 2:30 how many times can it go in to it
1 Vote
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i dont get negative numbers can someone plese help i cant get this
1 Vote
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Can somebody help me?
1 Vote
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What would you like help with?
1 Vote
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i thought the when the neg is bigger its alway a neg
1 Vote
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^-^ yay positive and negative ! hazahhhh
1 Vote
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At 2:33, Sal said "single bonds" but meant "covalent bonds."

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