In this lesson, we will use mental calculation strategies to add and subtract decimal numbers.

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!

1/6

Q2.If 1 is the whole and 0.8 is a part, what is the other part?

2/6

Q3.If 5 is the whole and 2.1 is a part, what is the other part?

3/6

Q4.If 10 is the whole and 7.3 is a part, what is the other part?

4/6

Q5.If 10 is the whole and 1.6 is a part, what is the other part?

5/6

Q6.If 10 is the whole and it is made of 3 parts. What could the parts be?

6/6

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!

1/6

Q2.If 1 is the whole and 0.8 is a part, what is the other part?

2/6

Q3.If 5 is the whole and 2.1 is a part, what is the other part?

3/6

Q4.If 10 is the whole and 7.3 is a part, what is the other part?

4/6

Q5.If 10 is the whole and 1.6 is a part, what is the other part?

5/6

Q6.If 10 is the whole and it is made of 3 parts. What could the parts be?

6/6

# 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.

Quiz:

Don’t worry if you get a question wrong! Forgetting is an important step in learning. We will recap next lesson.

1/6

Q2.What is 4 tenths add 3 tenths?

2/6

Q3.What is 9 tenths subtract 4 tenths?

3/6

4/6

Q5.What is 1.6 - 0.7?

5/6

Q6.What is 0.9 add 9 tenths?

6/6

Quiz:

Don’t worry if you get a question wrong! Forgetting is an important step in learning. We will recap next lesson.

1/6

Q2.What is 4 tenths add 3 tenths?

2/6

Q3.What is 9 tenths subtract 4 tenths?

3/6

4/6

Q5.What is 1.6 - 0.7?

5/6

Q6.What is 0.9 add 9 tenths?

6/6

# Lesson summary: Mental Addition and 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