Number (add/sub)

Hong Kong

Stage 1

Lesson

Here we're going to look at how we can make numbers by adding or taking away.

If we add two numbers together we are going to make a bigger number.

If we start with a number and take away we are going to make a smaller number.

Let's take a look at how we can make new numbers by adding or taking away.

Use the sliders below to try adding and taking away to make a new number!

Which of the following makes $16$16?

There may be more than one correct answer.

$8+8$8+8

A$9+8$9+8

B$9+9$9+9

C$8+7$8+7

D

Which of the following makes $6$6?

There may be more than one correct answer.

$8-2$8−2

A$13-10$13−10

B$12-6$12−6

C$15-9$15−9

D

Let’s play a game called target number. Here’s how it works. I give you a target number and starting number and you tell me what I need to get there.

For example, our target number is $20$20, and if I tell you the number $19$19 you would say $1$1, because $19+1=20$19+1=20.

Find the missing number below for our target number $20$20.

$18+\editable{}=20$18+=20

$13+\editable{}=20$13+=20

$20+\editable{}=20$20+=20