Module 1 Lesson 9Find related multiplication facts by adding and subtracting equal groups in array models.

Multiply by 2

5 x 2 = ______

Let’s skip count by 2 to find the answer!

2

4 6 8

10 5 x 2 = 10

Multiply by 2

4 x 2 = ______

Let’s skip count by 2 to find the answer!

2

4 6 8

4 x 2 = 8

Multiply by 2 Pattern Sheet Today we are going to complete our first

multiplication Pattern Sheet! Pattern Sheets are different from sprints

because: You complete one sheet only. You have 2 minutes to complete a

pattern sheet They are designed to be solved from

left to right across the page. We will pass out papers now. Leave them

face down on your desk and get your pencils ready.

Use your skip counting skills to solve any problems you don’t know the answer to right away!

Do your best work!

Multiply by 2 Pattern Sheet

2 minutes

End

Skip Count by 3s to 30 …

3 6 9 12 15 18 21 24 27 30

Skip Count by 4s to 40 … 4 8 12 16 20 24 28 32 36 40

Skip Count

Forms of MultiplicationWrite a repeated

addition sentence for this array.

Write a multiplication sentence for this array.

5 + 5 + 5 = 15

3 x 5 = 15

Forms of Multiplication

_____ fours = _____

3 12

Forms of Multiplication

Write two multiplication sentences for 2 groups of 7

2 x 7 = 147 x 2 = 14

Forms of Multiplication

Complete the equation

18 = 6 x _____3

Forms of Multiplication

5 threes = _____15

5 threes + 1 three = _____ threes

= _____ ones

6

18

Add Known Facts

Draw an array showing 5 rows of three.Write a multiplication sentence for the array:5 x 3

Add rows to your array so it shows 7 x 3. 2

7 threes = 5 threes + 2 threes7 x 3 = 5 x 3 + 2 x 3

How many threes did you add?

Add Known Facts

7 threes = 5 threes + 2 threes

7 x 3 = _____ x 3 + _____ x 3

______ = _____ + _____

5 2

21

15

6

Add Known Facts

__ threes = __ threes + __ threes

____ x 3 = ____ x 3 + ____ x 3

______ = _____ + _____

4 4

24

12

12

8

8 4 4

Subtract Known Facts

What multiplication fact does this array show?9 x 3

9 x 3 is not easy to solve … would 10 x 3 be easier?

10

Let’s use 10 threes to help us solve 9 x 3. I’ll mark our original array on the board.

Yes, because we could count by 10s.

20

30

Subtract Known FactsWe figured out that 10 x 3 = 30.How many 3s do we subtract to find 9 x 3?

1 three!

10 x 3 – 1 x 3 = ____ x 3

10

20

30

_____ -- _____= _____

9

30

3 27

Subtract Known Facts

__ threes = __ threes - __ threes

____ x 3 = ____ x 3 - ____ x 3

______ = _____ + _____

10

2

24

30

6

8

2

10

8

Distributive PropertyYou just used the DISTRIBUTIVE PROPERTY to solve those problems! The distributive property says that numbers can be broken apart or put together to make math problems easier to solve.

Example: 4 x 9 = 4 × 5 + 4 × 4

Think of the Distributive Property asthe LEGO property! “Distributive”means you can take apart a hardmath problem and put it backtogether in a way that is easierfor you to solve.

Problem Set