How_To_Be_Good_At_Math

CALCULATING • ADDITION 79

Adding as counting on

There is another way to think about addition.

To add one number to another, we can simply

count on from the larger number in a series of

steps that’s equal to the smaller number. This is

called counting on.

Then he counts on again by adding

the second red box to get 7.

Adding as counting all

We can think of addition as combining two or more

amounts into a single amount and then counting

them. This way of adding is called counting all.

Look at these balloons.

The robot has 2 balloons in

one hand and 5 in the other.

So, 2 + 5 = 7

2 + 5 = 7

Now the robot has

combined, or added, the

balloons by putting them all

together in one hand. We can

work out the total simply by

counting them all. There are 7.

7 balloons

altogether

2 orange

balloons

5 blue

balloons

2 + 5 =?

This time the robot is adding 5 blue

boxes and 2 red boxes. He can do

this by counting on from 5.

5 + 2 =? 5 + 2 = 7

5 blue

boxes

1 2

3 5

Count on 1

more from 6

to get 7

1 2

3 6

7

2 red

boxes

1 2

43 5 6

Count on 1 more

from 5 to get 6

First, he counts on by adding the first

red box to get 6.

4 4 5

078_079_Addition.indd 79 29/02/2016 18:56