**Year 4 Maths – Add and Subtract 2 Decimal Place Numbers and Money** *KS2 Revision*

## 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?

**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?

**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