Multiplying integers Review Slides- Lisi

Multiplying integers

Review and practice multiplying signed numbers

Poll

Rate your understanding of multiplying integers before you start this activity.

• I don’t get it.

• Sometimes I mess up.

• This is one of my strengths!

Integers are...

the set of all positive and negative whole numbers

{...-3, -2, -1, 0, 1, 2, 3...}

The signs on Integers follow these rules when multiplying

To help you remember the rules, think of love (+) and hate (-)

• if you love to love, that is love

• If you hate to hate, that is love

• If you love to hate, that is hate

• If you hate to love, that is hate

Multiple Choice

if you love to love, that is

• Love

• Hate

Multiple Choice

If you hate to love, that is...

• Love

• Hate

Multiple Choice

 $hate\left(-\right)\times love\left(+\right)=$  

•  $love+$  

•  $hate\ -$  

Multiple Select

Check all of the following that result in a positive (+)? 

•  $\left(-\right)\times\left(+\right)$  

•  $\left(-\right)\times\left(-\right)$  

•  $\left(+\right)\times\left(-\right)$  

•  $\left(+\right)\times\left(+\right)$  

Multiple Select

Check all of the following that result in a negative (-)? 

•  $\left(-\right)\times\left(+\right)$  

•  $\left(-\right)\times\left(-\right)$  

•  $\left(+\right)\times\left(-\right)$  

•  $\left(+\right)\times\left(+\right)$  

Follow the rules to multiply the integers

Observe these facts:

• We multiply the numbers as usual, no matter what the signs are.

• The sign after multiplying is determined by the rules.

• A positive number does not have to have a plus sign in front of it (+3=3)

• A negative number has to have a minus sign in front of it (-2=-2)

Multiple Choice

What is... $-3\cdot+2=$  

•  $-1$  

•  $-6$  

•  $+6$  

• None of these

Multiple Choice

What is $6\cdot-2=$   

•  $-12$  

•  $4$  

•  $+12$  

• None of these

Multiple Select

Which of the following is equal to $-12$   ?

(check all that do)

•  $3\cdot4$  

•  $3\cdot-4$  

•  $-3\cdot4$  

•  $-4\cdot3$  

•  $-4\cdot-3$  

Multiple Select

Check all the equations below that are correct.

•  $3\cdot-3=-9$  

•  $3\cdot3=9$  

•  $-3\cdot3=9$  

•  $-3\cdot-3=9$  

Multiple Choice

 $-1\cdot5=$  

• 4

• -4

• 5

• -5

Poll

Rate your understanding of multiplying integers after completing this activity.

• I still don’t get it.

• Sometimes I still mess up.

• This is now one of my strengths!

• Yep, I'm solid!