7th Math Module 2 Lesson 10

7th Math Module 2 Lesson 10

Understanding Multiplication of Integers.

What is multiplication?

Repeated addition.... thats it...

4 + 4 + 4 + 4 = 4 * 4

2 + 2 + 2 + 2 + 2 = 2 * 5

(-3) + (-3) + (-3) = 3 * (-3)

Let's warm up with a positave question

5 * 4 = ?

Open Ended

Please write (5 * 4) as an addition question.

Open Ended

Now, what is 4 + 4 + 4 + 4 + 4 ?

Multiplication is just repeated addition

What if the number being repeated is negative?

Open Ended

Please write the following as an addition question:

(-3) * 4 =

Open Ended

Now, what is (-3) + (-3) + (-3) + (-3) ?

Multiplication is just repeated addition

This is why the product of a negative and positive number is negative. All you are doing is adding a negative number by itself which makes it even more negative.

Multiple Choice

 $6\ \cdot\ \left(-3\right)\ =\ \left(-3\right)+\left(-3\right)+\left(-3\right)+\left(-3\right)+\left(-3\right)+\left(-3\right)$  

• True

• False

Multiple Choice

 $-5\cdot6\ =\ \left(-5\right)\left(-5\right)\left(-5\right)\left(-5\right)\left(-5\right)\left(-5\right)$  

• True

• False

Multiple Choice

 $7\cdot\left(-4\right)\ =\ \left(-4\right)+\left(-4\right)+\left(-4\right)+\left(-4\right)+\left(-4\right)+\left(-4\right)+\left(-4\right)$  

• True

• False

Open Ended

Write the following as Multiplication:

 $2+2+2+2$  

Open Ended

Write the following as Multiplication:

 $\left(-9\right)\ +\ \left(-9\right)\ +\ \left(-9\right)\ +\ \left(-9\right)\ +\ \left(-9\right)$  

Open Ended

Write the following as Multiplication:

 $\left(-7\right)\ +\ \left(-7\right)\ +\ \left(-7\right)\ +\ \left(-7\right)\$  

Multiple Choice

 $-5\ \cdot\ 3\ =\$  

• 2

• 8

• -15

• 15

Multiple Choice

 $11\ \cdot\ \left(-4\right)\ =\$  

• 44

• -44

• 7

• 15

Multiple Choice

 $8\ \cdot\ 3\ =\$  

• -24

• 24

• 11

• 5

Multiple Choice

 $-5\cdot6=$  

• -30

• 11

• 30

• 1

Multiple Choice

 $5\cdot\left(-2\right)=$  

• 3

• 10

• -10

• 7

Multiple Choice

 $-4\cdot7=$  

• 3

• 11

• -28

• 28