# Applying a range of strategies to mentally calculate subtraction

In this lesson, we will use different mental strategies to calculate subtraction such as partitioning, counting on and using known facts.

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

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

# Intro quiz - Recap from previous lesson

Before we start this lesson, let’s see what you can remember from this topic. Here’s a quick quiz!

Q1.What does the word 'efficient' mean?

1/4

Q2.Which of these is not a strategy for adding efficiently?

2/4

Q3.When adding 66 and 67 which is an efficient strategy?

3/4

Q4.When adding 69 and 81 which would be an efficient strategy?

4/4

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

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

# Intro quiz - Recap from previous lesson

Before we start this lesson, let’s see what you can remember from this topic. Here’s a quick quiz!

Q1.What does the word 'efficient' mean?

1/4

Q2.Which of these is not a strategy for adding efficiently?

2/4

Q3.When adding 66 and 67 which is an efficient strategy?

3/4

Q4.When adding 69 and 81 which would be an efficient strategy?

4/4

# 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:

# Applying a Range of Strategies to Mentally Calculate Subtraction Quiz

Are you a whizz at subtraction? Take the quiz to test your knowledge.

Q1.What does the word 'efficient' mean?

1/4

Q2.Which of these is not a strategy for subtracting efficiently?

2/4

Q3.When calculating 50 - 48 which is an efficient strategy?

3/4

Q4.When calculating 92 - 57 which would be an efficient strategy?

4/4

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

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

# Applying a Range of Strategies to Mentally Calculate Subtraction Quiz

Are you a whizz at subtraction? Take the quiz to test your knowledge.

Q1.What does the word 'efficient' mean?

1/4

Q2.Which of these is not a strategy for subtracting efficiently?

2/4

Q3.When calculating 50 - 48 which is an efficient strategy?

3/4

Q4.When calculating 92 - 57 which would be an efficient strategy?

4/4

# Lesson summary: Applying a range of strategies to mentally calculate subtraction

## Time to move!

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

For 5 mins...

Move around:
Climb stairs

On the spot:
Chair yoga