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Quick Math Homework Help

Multiplying negative numbers and fractions

Remember our rules for multiplying positive and negative numbers?

" Negatives always come in pairs"

or

​" Same signs = positive "
  Different signs = negative"

These same rules apply to fractions. For example:

(-1/6) * 2/3 = -2/18 = -1/9

(-1/6) * (-2/3) = 1/9

1/6 * 2/3 = 1/9


Whenever you have a negative base and an exponent you need to be on the lookout for parenthesis.
If you have a negative base and  parenthesis, the parenthesis applies to the base. An example will help.

( -6^2) = -6 * -6 =36
compare this to
-6^2 = -6 * 6 = -36

-4^2 = -4*4=16
compare this to 
(-4^2) = -4 * -4 = 16 

** Negative * Negative = Positive


Multiplying negative numbers and exponents

Whenever you multiply a number by zero your answer will be zero. Regardless if the number is positive or negative, the answer is zero.

For example:
3 x0 = 0
-5 x 0 = 0
-456 x 0 =0

Multiplying a negative number by zero

rectangle green header moomoomath rules positive negative integers

Tip for Multiplying Negative Numbers

Help,when I multiply or divide positive and negative integers I don't know if the answer is positive or negative.

Fortunatly there are rules to help with this. Two quick and easy ways to remember the rules are:

" Negatives always come in pairs"
or

​" Same signs = positive "
  Different signs = negative"

Notice the negatives are always in pairs
Quick and easy method to remember: 

Same signs = positive  quotient

Different signs =negative quotient

6*2 = 12
6*-2 = -12
-6 *-2 = 12

Welcome to MooMooMath. Today we are talking multiplication of sign numbers, so here are our examples. Negative four times negative five is equal to positive twenty. Positive five times negative two is negative ten, and negative eight times positive three is equal to twenty four. There are our examples. Now let’s go look at our rules. Here are the rules of multiplication. Negative times a negative is positive. The way I think about it is that negatives always come in pairs so they pair up and become a positive. So if you have negative times a positive the negative doesn’t have a pair therefore the answer is negative. The negatives always come in pairs. A positive times a negative is a negative, and positive times a positive is a positive. So always think of negatives coming in pairs. So now let’s go back and look at our example problems. The rules are a negative times negative is equal to a positive. They have paired up and become a positive so negative four times five is positive twenty. A positive needs a pair so the answer is negative so five times two is negative ten. Negative times a positive is a negative so three times eight is twenty four and it will be negative. So let’s look at the challenge problem. I have negative one times a negative one times a negative one. If I pair my negatives up these two will pair up and become a positive and these two pair and become a positive so the answer is just a positive times a positive which a positive is. So the answer to that challenge problem is positive one.
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Transcript 

Multiplication of Negative and Positive Numbers-7th grade Math

Rules for Multiplying Negative and Positive Integers

infographic rules multiplying positive negative numbers
Here are a few examples of multiplying positive and negative numbers.
 -4x5= -20 

  5 x -2= -10  

 -8x-3 = 24
rules multiplying positive negative integers
Common Core Standard: 7ns.2.b