Functional Skills Maths: Decimals

Work with numbers that include parts

What are Decimals?

  • Decimals use a dot (.) to show parts smaller than 1.
  • 0.5 = half (the same as ½).
  • 0.25 = one quarter.
  • Money uses decimals: £3.50 = £3 and 50 pence.

Adding and Subtracting Decimals

  • Line up the decimal points when adding or subtracting.
  • 1.5 + 2.3 = 3.8 (ones: 1+2=3, tenths: 5+3=8).
  • 5.7 − 3.2 = 2.5
  • Always keep the dot in the same place.

Comparing Decimals

  • To compare, look at the digits from left to right.
  • 0.9 is bigger than 0.75 (9 tenths > 7 tenths).
  • 0.5 = 0.50 (adding a zero after does not change the value).

Worked Examples

Example 1: £4.50 + £3.25

  1. Line up the decimal points.
  2. Pence (hundredths): 50 + 25 = 75.
  3. Pounds: 4 + 3 = 7.
  4. Answer: £7.75

Example 2: 6.8 − 3.2

  1. Tenths: 8 − 2 = 6.
  2. Ones: 6 − 3 = 3.
  3. Answer: 3.6

Practice Questions

  • 2.5 + 3.5 = ?
    Hint: Tenths: 5+5=10, write 0 carry 1. Ones: 2+3+1=6.
    Answer: 6.0
  • 7.8 − 4.3 = ?
    Hint: Tenths: 8−3=5. Ones: 7−4=3.
    Answer: 3.5
  • £5.60 + £2.40 = ?
    Hint: Pence: 60+40=100 (£1). Pounds: £5+£2+£1=£8.
    Answer: £8.00
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