Multiplying and Dividing Integers Mrs. Young EMC 1

Rules When multiplying and dividing integers there are two rules: When multiplying or dividing integers that have the SAME sign, the answer is POSITIVE. Positive x positive = positive Negative x negative = positive +7 x +12 = +84 -6 x –5 = +30

Rules continued… Rule 2: When multiplying or dividing integers whose signs are DIFFERENT, the answer will always be NEGATIVE. Positive x negative = negative Negative x positive = negative +8 x –4 = -32 -5 x +7 = -35

Multiplying Integers Song Let’s Sing a Song! Multiplying Integers Song (sing to “Dead Bones” tune) Verse 1  A negative times a negative is a, (um) positive  A negative times a positive is a, (um) negative A negative times a negative is a, (um) positive These are the rules for signs. Verse 2  If you have the same signs, you get a positive,  But if they’re different, you get a negative, If you have the same signs, you get a positive, Yes, these are the rules for signs. 

Let’s Practice! What sign would the answer have in front of the integer??? -5 x -7 = ???

POSITIVE!!!

What sign will be in front of the answer?? How about… -6 x 9 = ??? What sign will be in front of the answer??

NEGATIVE!!!

Try this one! What sign will be in front of the answer??? -81 ÷ +9 = ???

NEGATIVE!!!

Let’s solve some problems! -8 x –9 =

+72

+4 x +12 =

+48

-45 ÷ +5 =

-9

-63 ÷ +7 =

-9

-8 x –11 =

+88

Remember… When multiplying and dividing integers: Same signs = a positive Different signs = a negative