Lesson

Do you remember how to add numbers together, like 3 and 4?

The image below shows one group of apples being added to another.

How many apples are there in total?

Worked Solution

Idea summary

To add numbers together, we can use counting or the number line.

Let's see how 3, 4 and 7 are related and make a fact family.

Here is the fact family of 2, 5 and 7.

a

What is 2 + 5?

Worked Solution

b

What is 7 - 5?

Worked Solution

c

What is 7 - 2?

Worked Solution

Idea summary

A fact family has three numbers that are connected in some way. In this case, they are connected by addition and subtraction.

uses mental and written strategies for addition and subtraction involving two-, three-, four and five-digit numbers