# Subtracting three-digit numbers

## Home learning focus

In this lesson, you will learn how to add three-digit numbers together.

The lesson includes:

• two videos
• two online activities
• two activity sheets

# Learn

Do you know how to subtract numbers from each other? Find out by watching this short animation featuring a terror from the deep from KS2 Maths.

If the numbers are too high or too difficult to subtract in your head, write them down in columns. Separate the numbers into ones, tens and hundreds. List the numbers in a column and always start with the ones first.

• Estimate first and check afterwards. It's a good idea to estimate a rough answer first and always check your actual answer.
• Subtraction is the opposite to addition. So subtraction can always be checked by adding. Check that 182 - 37 = 145 by doing the sum: 145 + 37 = 182
• Look out for these words in problems: take away, difference, less than, minus, decrease, fewer than, reduce. They all indicate subtraction.

## Column subtraction

Numbers can also be subtracted using the column method.

## What is 548 - 125? Start from the ones column: 8 - 5 = 31 of 4 In the tens column: 40 - 20 = 20. 2 is written in tens column as this is worth 202 of 4 In the hundreds column: 500 - 100 = 400. 4 is written in the hundreds column as this is worth 4003 of 4 The finished subtraction - 4234 of 4

When subtracting two numbers in a place value column, if the second number is larger than the first it cannot be subtracted. You need to exchange a digit from a higher column.

## What is 343 - 237? Start from the ones column: 3 - 71 of 5 It is not possible to subtract 7 from 3 so exchange one ten from the tens column for ten units: 13 - 7 = 62 of 5 In the tens column, one 10 has been exchanged so 40 becomes 30: 30 – 30 = 03 of 5 In the hundreds column: 300 - 200 = 100. 1 is written in the hundreds column as this is worth 1004 of 5 The finished subtraction - 1065 of 5

# Practise

## Activity 1

Simple subtraction

Click on the image below to see if you can subtract the numbers correctly.

## Activity 2

Some more simple subtraction

Click on the image below to see if you can subtract the numbers correctly.

## Activity 3

Subtracting three-digit numbers

Test your knowledge of three-digit numbers with this worksheet from Twinkl.

## Activity 3

Three-digit numbers game

Put your knowledge of three-digit numbers through its paces with this fun active learning game from Move & Learn.

All you need is a pack of playing cards, some paper, a pen and a container.

# There's more to learn

Have a look at these other resources around the BBC and the web.