Objectives

I can match equations and tape diagrams that represent the same situation.

If I have an equation, I can draw a tape diagram that shows the same relationship.

Online Workbook

Take me to the website.

Llévame al sitio web.

Lesson Summary

We have seen how tape diagrams represent relationships between quantities. Because of the meaning and properties of addition and multiplication, more than one equation can often be used to represent a single tape diagram.

Let’s take a look at two tape diagrams.

We can describe this diagram with several different equations. Here are some of them:

26+4x=46, because the parts add up to the whole.
4x+26=46, because addition is commutative.
46=4x+26, because if two quantities are equal, it doesn’t matter how we arrange them around the equal sign.
4x=46−26, because one part (the part made up of 4 x’s) is the difference between the whole and the other part.

For this diagram:

4(x+9)=76, because multiplication means having multiple groups of the same size.
(x+9)⋅4=76, because multiplication is commutative.
76÷4=x+9, because division tells us the size of each equal part.