Bar Model — 7 + 8 = 15 — free printable diagram

What is 7 + 8?

This part-whole bar model shows 7 and 8 as the two parts of one whole. Adding the parts gives the whole, so 7 + 8 = 15.

First part

7

Second part

8

Whole

15

Addition

7 + 8 = 15

Subtraction

15 − 7 = 8

• A part-whole bar model shows the whole on one bar and the parts that make it on the bar underneath. Here the two parts are 7 and 8, and together they fill the whole bar of 15.
• The parts can be added in either order — swapping them does not change the whole: 7 + 8 = 8 + 7 = 15.
• Covering up one part turns the same picture into a subtraction: 15 − 7 = 8 and 15 − 8 = 7.
• That is the fact family for these three numbers — the model is the reason 7, 8 and 15 belong together, whichever way round you write them.