Module 1 Lesson 9 Find 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! x 2 = 10

Multiply by 2 4 x 2 = ______ Let’s skip count by 2 to find the answer! 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 … Skip Count by 4s to 40 … Skip Count

Forms of Multiplication Write a repeated addition sentence for this array. Write a multiplication sentence for this array = 15 3 x 5 = 15

Forms of Multiplication _____ fours = _____

Forms of Multiplication Write two multiplication sentences for 2 groups of 7 2 x 7 = 14 7 x 2 = 14

Forms of Multiplication Complete the equation 18 = 6 x _____ 3 3

Forms of Multiplication 5 threes = _____ 15 5 threes + 1 three = _____ threes = _____ ones

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. 7 threes = 5 threes + 2 threes 7 x 3 = 5 x x 3 How many threes did you add?

Add Known Facts 7 threes = 5 threes + 2 threes 7 x 3 = _____ x 3 + _____ x 3 ______ = _____ + _____

Add Known Facts __ threes = __ threes + __ threes ____ x 3 = ____ x 3 + ____ x 3 ______ = _____ + _____

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? 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.

Subtract Known Facts We 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 _____ -- _____= _____

Subtract Known Facts __ threes = __ threes - __ threes ____ x 3 = ____ x 3 - ____ x 3 ______ = _____ + _____

Distributive Property You 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 × × 4 Think of the Distributive Property as the LEGO property! “Distributive” means you can take apart a hard math problem and put it back together in a way that is easier for you to solve.

Problem Set