Bar Model — 1 + 1 = 2 — free printable diagram

What is 1 + 1?

This part-whole bar model shows 1 and 1 as the two parts of one whole. Adding the parts gives the whole, so 1 + 1 = 2.

First part

1

Second part

1

Whole

2

Addition

1 + 1 = 2

Subtraction

2 − 1 = 1

• 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 1 and 1, and together they fill the whole bar of 2.
• Both parts are the same size, so this is a doubling fact: double 1 is 2.
• Reading it backwards gives the matching halving fact: 2 split into two equal parts is 1 each, so 2 ÷ 2 = 1.
• That is the fact family for these three numbers — the model is the reason 1, 1 and 2 belong together, whichever way round you write them.