# Deriving addition and subtraction facts

In this lesson, we will derive addition and subtraction facts by using part whole models to show how related facts can be derived from scaling up by 10, 100 or 1000.

# Video

Click on the play button to start the video. If your teacher asks you to pause the video and look at the worksheet you should:

• Click "Close Video"
• Click "Next" to view the activity

Your video will re-appear on the next page, and will stay paused in the right place.

# Worksheet

These slides will take you through some tasks for the lesson. If you need to re-play the video, click the ‘Resume Video’ icon. If you are asked to add answers to the slides, first download or print out the worksheet. Once you have finished all the tasks, click ‘Next’ below.

#### Unit quizzes are being retired in August 2023

Why we're removing unit quizzes from the website >
Quiz:

# Deriving addition and subtraction facts

Using what we have learnt today, can you answer the following questions?

Q1.If I know 3 + 3 = 6, then I know...

1/5

Q2.If I know 3 + 5 = 8, then I know...

2/5

Q3.What's the missing part in the following equation: 220 + ___ = 550

3/5

Q4.What's the missing part in the following equation: 110 + ___ = 660

4/5

Q5.Here are three derived facts, based on the fact 3 + 5 = 8. Which is incorrect?

5/5

#### Unit quizzes are being retired in August 2023

Why we're removing unit quizzes from the website >
Quiz:

# Deriving addition and subtraction facts

Using what we have learnt today, can you answer the following questions?

Q1.If I know 3 + 3 = 6, then I know...

1/5

Q2.If I know 3 + 5 = 8, then I know...

2/5

Q3.What's the missing part in the following equation: 220 + ___ = 550

3/5

Q4.What's the missing part in the following equation: 110 + ___ = 660

4/5

Q5.Here are three derived facts, based on the fact 3 + 5 = 8. Which is incorrect?

5/5

# Lesson summary: Deriving addition and subtraction facts

## Time to move!

Did you know that exercise helps your concentration and ability to learn?

For 5 mins...

Move around:
Walk

On the spot:
Dance