Commutative Property of

MultiplicationMAFS.3.OA.2.5

Commutative Property of MultiplicationIn Ms. Adams’s classroom library, she has 5 rows of bookshelves with 3 books on each shelf, as shown

below.

Commutative Property of MultiplicationIn Ms. Prescott’s classroom library, she has 3 rows of

bookshelves with 5 books on each shelf, as shown below.

Commutative Property of MultiplicationWho has more books?

Ms. Adams Ms. Prescott

Commutative Property of MultiplicationWrite a multiplication sentence that models each

picture.

Ms. Adams Ms. Prescott

5 × 3 = 15 3 × 5 = 15

Commutative Property of MultiplicationSo who has more books?

They have the same number of books.

Ms. Adams Ms. Prescott

5 × 3 = 15 3 × 5 = 15

Commutative Property of Multiplication

That means that

has the same value as…

5 × 3 = 15

3 × 5 = 15This is because of the Commutative Property of Multiplication

which states that when you change the order of the factors, the

product stays the same.

Let’s model the Commutative Property of Multiplication.

With counters or square tiles, model 3 rows of 5.

3 x 5 = 15

Now, model 5 rows of 3.Doesn’t it look like the same array, just turned on its side?

It is.

5 x 3 = 15

Model 3 groups of 4.

Let’s model the Commutative Property of Multiplication.

3 x 4 = 12

Model 4 groups of 3.

4 x 3 = 12

Do the models look the same? NOBut, is the product the same? YES!

Write 2 multiplication equations for the following array.

3 × 5 = 155 × 3 = 15

Write 2 multiplication equations for the following array.

5 × 4 = 204 × 5 = 20

Write 2 multiplication equations for the following array.

2 × 4 = 84 × 2 = 8

Write 2 multiplication equations for the following array.

3 × 6 = 186 × 3 = 18

Why is the Commutative Property important?

If you know your “easy” facts, like

your 1s, 2s, 5s, and 10s…

Then you also know many of your other

facts too…all because of the Commutative

Property of Multiplication.

Exit TicketWrite the two multiplication equations shown by the arrays below.

What number would make this equation true?

5 × 4 = × 5