Subtract a 1-digit number from a 3-digit number

Subtraction is when you take away a number or an amount from another number or amount to work out what is left.

There are different things you can use to help you subtract. You can use number lines, place value charts and place value counters.

Knowing your number bonds and how to partition numbers can make subtraction easier. It can even help you to do it in your head.

Quiz: Subtracting a 1-digit number from a 3-digit number

Test out your knowledge of subtracting a 1-digit number from a 3-digit number with this quiz, then read on to complete the page.

It can help to break a number down into hundreds, tens and ones when you are subtracting.

Let's take a look at an example.

'A class has 245 pencils. If Fred needs 7 pencils to draw his picture, how many pencils are left?'

Using the information in this question, you need to work out:

245 - 7

Let's start by breaking the number 245 into hundreds, tens and ones.

Subtracting using a number line

Knowing your number bonds to 10 can really help with subtraction.

Sometimes, you might need to cross over a ten to find the answer. This is called bridging a ten, which means going past the ten.

You can use a number line to help you count back and bridge a ten while subtracting.

Let's look at an example:

353 - 6

To work out 353 - 6, start on 353 and count back 6.

You'll bridge the ten at the number 350.

353 - 6 = 347

Another way to bridge a 10 when subtracting is to break up the 1-digit number.

Let’s work out the answer to another calculation:

595 - 7

Start by putting 595 on your number line.

Next, find the nearest ten below 595. That’s 590. Mark this on the number line and jump back.

595 is 5 away from 590. You have to jump back 5.

Now, you still need to take away 2 more. This is because the original 7 has been split into 5 and 2. You have only taken away 5 so far.

So subtract 2 from 590.

If you know that 10 – 2 = 8, you can use that to help.

590 - 2 = 588

Therefore the answer is:

595 - 7 = 588

Finding the difference

Here is a missing number problem.

To solve this problem you need to find the difference between 284 and 291.

There are two ways of working this out using a number line.

You can use subtraction…

Start at the greatest number, 291, and jump back to the nearest multiple of ten, which is 290. Then jump back to the smallest number, 286.

Using the number line you can see:

291 − 1 − 4 = 286

You have subtracted 5 altogether, so the missing number is 5.

291 − 5 = 286

Or, you can also use addition…

Start at the smallest number, 286, jump onto the next multiple of ten, which is 290, then jump on to 291.

Using the number line you can see:

286 + 4 + 1 = 291

The answer is 5 again:

291 - 5 = 286

Use your knowledge of hundreds, tens and ones to complete the number sentence shown in the picture below.