What you need to know

Things to remember:

  • Decimal amounts of money can split into two pieces, £ and pence.
  • We look at £ together and pence together.

When adding and subtracting money, we do this in 4 steps.

What is £2.40 + £3.30?

Step 1: Split into £ and into pence.

£2.40 is £2 and 40p

£3.30 is £3 and 30p

Step 2: Add the £

£2 + £3 = £5

Step 3: Add the pence

40p + 30p = 70p

Step 4: Put Step 2 and Step 3 together.

£5 and 70p is £5.70

£2.40 + £3.30 = £5.70

Sometimes though, the pence will give us an extra £ that we have to add.

What is £2.40 + £3.70?

Step 1: Split into £ and into pence.

£2.40 is £2 and 40p

£3.70 is £3 and 70p

Step 2: Add the £

£2 + £3 = £5

Step 3: Add the pence

40p + 70p = 110p

110p is £1 and 10p

Step 4: Put Step 2 and Step 3 together.

£5 and £1 and 10p is £6 and 10p

£2.40 + £3.70 = £6.10

What is £5.40 – £1.20?

Step 1: Split into £ and into pence.

£5.40 is £5 and 40p

£1.20 is £1 and 20p

Step 2: Subtract the £

£5 – £1 = £4

Step 3: Subtract the pence

40p – 20p = 20p

Step 4: Put Step 2 and Step 3 together.

£4 and 20p is £4.20

£5.40 + £1.20 = £4.20

Sometimes though, the pence will go into negative numbers, so we’ll have to borrow a £.

What is £6.20 – £3.50?

Step 1: Split into £ and into pence.

£6.20 is £6 and 20p

£3.50 is £3 and 50p

Step 2: Subtract the £

£6 – £3 = £3

Step 3: Subtract the pence

20p – 50p = -30p

Step 4: Put Step 2 and Step 3 together.

£3 and -30p

But we can’t really have “£3 and -30p”, so let’s borrow one of those £.

Step 5: Borrow one of the £s.

£3 and -30p

£2 and £1 and -30p

Step 6: Covert the £ into pence and subtract

£2 and 100p and -30p

100 – 30p = 70p

£2 and 70p

£6.20 – £3.50 = £2.70

Example Questions

Question 1: What is £6.60 + £2.90?

Answer

Step 1: Split into £ and into pence.

 

£6.60 is £6 and 60p

£2.90 is £2 and 90p

 

Step 2: Add the £

 

£6 + £2 = £8

 

Step 3: Add the pence

 

60p + 90p = 150p

150p is £1 and 50p

 

Step 4: Put Step 2 and Step 3 together.

 

£8 and £1 and 50p is £9 and 50p

£6.60 + £2.90 = £9.50

Question 2: What is £3.40 – £2.60?

Answer

Step 1: Split into £ and into pence.

 

£3.40 is £3 and 40p

£2.60 is £2 and 60p

 

Step 2: Subtract the £

 

£3 – £2 = £1

 

Step 3: Subtract the pence

 

40p – 60p = -20p

 

Step 4: Put Step 2 and Step 3 together.

 

£1 and -20p

 

But we can’t really have “£1 and -20p”, so let’s convert the £ into pence.

 

Step 5: Covert the £ into pence and subtract

 

100p and -20p

100 – 20p = 80p

£3.40 – £2.60 = 80p