The Associative Property of Multiplication for 3rd-Grade

The associative property of multiplication for 3rd-Grade allows students to change grouping of an expression to make it easier to solve. The property displays to students that the grouping of factors do not matter, the product will be the same. 

What is the Associative Property of Multiplication?

The associative property of multiplication states that the grouping of a multiplication sentence does not matter, the product will be the same. So in other words, the parenthesis can move on each expression, but the numbers do not change places, and the product will be the same. Look at the equation below.

For example:

3 × (5 × 7) = (3 × 5) × 7

Notice how the parenthesis are what changes the grouping in the expression. The product will in fact be the same, and the numbers DO NOT change places.

Also, it's important to teach your students to multiply inside the parenthesis first (PEMDAS or GEMDAS). If students have built a strong mathematical base they will not struggle when they start using algebra. This is why it is also important as math teachers to use the terms students are going to hear in algebra like equation, factor, and expression.

Expressions do not have equal (=) signs. 

For example:

3 × (5 × 7)

A factor is a number when multiplied by another number it gives and expression.

3 × 5

Equations have equal (=) signs.

For example:

3 × (5 × 7) = (3 × 5) × 7

Personally, I like to use the term multiplication sentence, number sentence, and division sentence as well. 

The sad truth is that their isn't many activities out there for the associative property of multiplication. As a mathematics teacher-author I am trying to change that. Check out this unit I created for the associative property.

As teachers it our chance to change the negative stigma on math. I remember, after 3rd-grade I hated math. It wasn't until a college class I took at a local community college that I learned to appreciate mathematics. My teacher brought in Dollar Store erasers to explain something. She changed my life with those little erasers... she probably doesn't even know.