Eureka Module 3 Lesson 2

Eureka Module 3 Lesson 2

The Commutative Property

• The Commutative Property tells us that we can switch the order of factors in a multiplication equation and they will both have the same product (answer).

• Examples:

• 7x3 =3x7

• 4 eights= 8 fours

Multiple Choice

Using the commutative property, find the matching multiplication equation for 8x3=24

• 6x4=24

• 8 +3 =24

• 3x8=24

• 24-8=3

Multiple Choice

Using the commutative property, find the matching unit form of 7 nines

• 6 nines

• 7 eights

• 7 sevens

• 9 sevens

Multiplication Representation

• We can represent the value of a group using objects.

• Example- Each block has a value of seven. There are 4 sevens. We can use the multiplication equation 4x7 to solve.

• Example- Each circle has a value of 8. There are 5 eights. We can use the multiplication 8x5 to solve.

Fill in the Blanks

Write and solve a multiplication equation to match the picture. (Do not use spaces when typing!)

Fill in the Blanks

Write and solve a multiplication equation to match the picture. (Do not use spaces when typing!)

Decomposing Larger Equations

• We can use smaller multiplication facts that we already know to help us learn larger multiplication facts.

• One of the easiest fact families to use is the fives family.

• To multiply by fives, we can count by fives!

• Then we can add on the product of the smaller equation to find the product of the larger equation

Jen writes 9 pages each week. How many pages does she write in 7 weeks? Use a 5s fact to solve.

• First I set up my picture by creating 7 circles for 7 weeks.

• Next I give each circle a value of 9 because that's how many pages she writes each week.

• I can split the 7 nines into 2 nines +5 nines to use a five fact

• I can multiply 5x9 and I know the product is 45.

• I can multiply 2x9 and I know the product is 18.

• I can add to two products of 2 nines and 5 nines (2x9)+ (5x9)= 18 +45= 63

• Therefore 7 nines, or 7x9=63

Multiple Choice

Which of the following pictures shows the CORRECT way to solve 8x6 using a fives fact?

Now let's use what we've learned to practice some multiplication facts!

Get ready!

Multiple Choice

7x9=

• 56

• 63

• 49

Multiple Choice

8x7=

• 56

• 63

• 49

Multiple Choice

7x8=

• 56

• 63

• 49

Multiple Choice

7x7=

• 14

• 49

• 56

Multiple Choice

7x10=

• 70

• 60

• 77