Multiplying and Dividing Integers: The Basics

Multiplying and Dividing Integers

Or Rational Numbers

Take a minute to look at this image

Do you notice a pattern? Answer on the next slide

Multiple Choice

Did you notice a pattern in the following?

• Yes

• No

• Maybe

• I don't know

Open Ended

Explain the pattern you noticed in the space provided

Poll

Do you remember learning about Rational Numbers?

• Yes

• No

• I am not sure

• When did we learn that?

The patterns

Multiplying: -6, -8, 0, 6, 8

Dividing: -3, 4, -3, 4

Rational Numbers

Any number that can be written as a fraction

Multiple Select

Are you still unsure about what to do when multiplying and dividing?

• Yes

• No

If you need a second look at the video —>

Vocabulary

• Absolute Value:

You multiply or divide integers just as you do whole numbers, except you must keep track of the signs. 

To multiply or divide signed integers, always multiply or divide the absolute values and use these rules to determine the sign of the answer.

Multiplying Integers

and the basic rules

When you multiply two integers with the same signs, the result is always positive. Just multiply the absolute values and make the answer positive.

Positive x positive = positive

Negative x negative = positive

When you multiply two integers with different signs, the result is always negative. Just multiply the absolute values and make the answer negative.

Positive x negative = negative

Negative x positive = negative

Dividing Integers

and the basic rules

When you divide two integers with different signs, the result is always negative. Just divide the absolute values and make the answer negative.

When you divide two integers with different signs, the result is always negative. Just divide the absolute values and make the answer negative.

Positive ÷ negative = negative

Negative ÷ positive = negative

Here are the rules as a visual reminder

This is also on Google Classroom

Multiplying – Try this with me...

Example:

-5*-4=

20

Why?

- Rule: a negative times a negative is a positive

Dividing – Try this with me...

Example:

-10/5=

-2

Why?

- Rule: a negative divided by a negative is a negative

Poll

Do you understand enough to try it yourself?

• Yes

• No

• Can we do more examples?

Let's try these together!

Multiply:

1. -3*8

Divide

2. -12*4

Multiple Choice

Solve:

 $-4\times2$  

• -8

• -2

• 6

• 8

Multiple Choice

Solve:

 $-3\times-2$  

• -8

• -2

• 6

• 8

Multiple Choice

Solve:

 $-6\div3$  

• -8

• -2

• 6

• 8

Multiple Choice

Solve:

 $-8\div-4$  

• -8

• 2

• 6

• -2