Mathematics

Intermediate

50 mins

Teacher/Student led

Learning Goals

Learning Outcomes

Lesson Files

+80 XP

What you need:
IWB/Projector/Large Screen

Subtracting Decimals

Learn to subtract decimals by lining up the decimal points, adding trailing zeros, and regrouping tenths into hundredths using the same ten-for-one trade you already know.

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1 Getting Started
2 Watch and Notice
3 Try It Together
4 Set up and Subtract in Your Copy
5 Class Challenge
6 What Did We Notice?
7 What's Next
Pupil practice

1 - Getting Started ~4 mins

Key point

Look hard at where the decimal points sit and where each digit lands. You already know one rule that keeps everything in order when we work with decimals. Does that same rule seem to be holding here?

Illustration for Getting Started Here is a subtraction laid out ready to work: 4.5 − 1.75. Is this layout right, or is something wrong with it?

👇 Mark your steps as done as you complete them.

+5 XP

2 - Watch and Notice ~9 mins

The interactive shows three decimal subtractions lined up in columns. Notice how a missing digit is filled with a zero, and how each trade is the same one you already know, just further right.

👇 Mark your steps as done as you complete them.

+10 XP

3 - Try It Together ~8 mins

Key point

Let's work this one together on the board, lining the decimal points up first: 3.8 − 1.45. Notice that 3.8 has no hundredths written, so we make it 3.80 to give the hundredths column a partner before we subtract.

Line up the points, then subtract

+15 XP

4 - Set up and Subtract in Your Copy ~4 mins

COPYBOOK MOMENT

Illustration for Set Up and Subtract in Your Copy In your maths copy, set up each of these decimal subtractions vertically, with the decimal points lined up in one straight column. Write in any trailing zeros you need so both numbers have the same number of decimal places.

2.4 − 1.36
0.5 − 0.28
3.00 − 1.65

Then work each one column by column and circle every regroup you make.

+10 XP

5 - Class Challenge ~8 mins

Key point

Line the points up first every time, and predict where the trade will have to travel before we check:

Today we work through these together on the board, each one a step harder than the last.

4.6 − 2.35
3.0 − 1.48
7.25 − 3.9
10.0 − 4.55

Decimal subtraction: line up and regroup

+15 XP

Pupil practice

Module 2 · Operations and Computational Fluency Number

Lesson 22 · Subtracting Decimals

Download Activity Book page (PDF)

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Subtracting Decimals

Teacher Class Feed

1 - Getting Started ~4 mins

2 - Watch and Notice ~9 mins

3 - Try It Together ~8 mins

Line up the points, then subtract

4 - Set up and Subtract in Your Copy ~4 mins

5 - Class Challenge ~8 mins

Decimal subtraction: line up and regroup

Unlock the full learning experience

XP