Commutative Property of Multiplication MAFS.3.OA.2.5

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

Commutative Property of Multiplication In Ms. Prescott’s classroom library, she has 3 rows of bookshelves with 5 books on each shelf, as shown below.

Commutative Property of Multiplication Who has more books? Ms. Adams Ms. Prescott

Commutative Property of Multiplication Write a multiplication sentence that models each picture. Ms. Adams Ms. Prescott

Commutative Property of Multiplication So who has more books? They have the same number of books. Ms. Adams Ms. Prescott

Commutative Property of Multiplication That means that has the same value as… This 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? But, is the product the same?

Write 2 multiplication equations for the following array.

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 Ticket Write the two multiplication equations shown by the arrays below. What number would make this equation true? 5 × 4 = × 5