DOL Lesson 7

Look at the arrays in the picture. Do you agree or disagree with this statement:

2 x 5 = 5 x 2

• They are NOT the same because the arrays have different totals.

• They are NOT the same because the arrays do NOT have 10 circles.

• They are the same because the total is 10 in both arrays.

• They are the same because the total is 5 in both arrays.

Answer explanation

2 x 5 = 10. The array has 10 circles.

5 x 2 = 10. The array has 10 circles.

That means that both arrays has the same number of circles.

So, 2 x 5 is the same as 5 x 2.

Mary Beth organizes stickers on a page in her sticker book.

She arranges them in 3 rows and 4 columns.

1. Which array shows Mary Beth’s stickers?

• 
• 
• 

Answer explanation

A 3 x 4 array means that there are 3 rows and 4 objects in each row, for a total of 12.

Mary Beth organizes stickers on a page in her sticker book.

She arranges them in 3 rows and 4 columns.

1. Use your array to write a multiplication sentence to find Mary Beth’s total number of stickers.

• 4 + 3 = 12

• 3 + 4 = 7

• 4 x 3 = 12

• 3 x 4 = 12

Answer explanation

A 3 x 4 array means that there are 3 rows and 4 objects in each row, for a total of 12.

How do you skip-count to solve your multiplication sentence 3 x 4 = 12?

• 3, 6, 9, 12

• 4, 8, 12

• 2, 4, 6, 8, 10, 12

• 6, 12

Answer explanation

Because there are 3 rows and 4 objects in each row, you will be counting by 4's three times until you get to 12.

Use what you know about the commutative property to select a different multiplication sentence for your array.

• 4 x 4 = 12

• 3 x 3 = 12

• 2 x 6 = 12

• 4 x 3 = 12

Answer explanation

The Commutative Properties shows us that 3 x 4 is equal to 4 x 3 because both have the same number 12 as a total.

Write and solve the multiplication sentences for these two arrays.

• 2 x 3 = 6

  3 x 2 = 6

• 2 x 4 = 8

  4 x 2 = 8

• 2 x 6 = 12

  6 x 2 = 12

• 2 x 5 = 10

  5 x 2 = 10

Answer explanation

The Commutative Properties shows us that 2 x 4 is equal to 4 x 2 because both have the same number 8 as a total.

Patricia buys bottles of soap. Each bottle costs $4.

How much money does Patricia spend if she buys 5 bottles of soap?

• $4 + 5 = $9

• 5 x $4 = $20

• 5 - $4 = $1

• 20 ÷ $4 = $5

Answer explanation

$4 repeats 5 times.

I have to multiply 5 x $4 = 20.

Patricia buys bottles of soap. Each bottle costs $4.

How much money does Patricia spend if she buys 8 bottles of soap?

• 4 x $8 = $32

• 8 x $4 = $32

• 8 + $4 = $12

• 8 - $4 = $4

Answer explanation

$4 repeats 8 times.

I have to multiply 8 x $4 = 32.

How does skip-counting help solve multiplication problems?

• It helps us count in equal groups to reach a number.

• Skip-counting does not help in multiplication.

• Skip-counting tells you which numbers you need to multiply.

Answer explanation

In order to solve 5 x 2 = ? skip counting will tell you to count 5 times by 2s, like this: 2, 4, 6, 8, 10.

The last number, number 10, is the answer to 5 x 2 = 10