GCSE Maths Practice: decimals

Question 5 of 10

This foundation GCSE Maths question practises dividing a decimal by a whole number. It strengthens understanding of place value and prepares you for questions involving money, ratios, and unit costs.

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\( \begin{array}{l}\textbf{Calculate } 4.8 \div 3.\end{array} \)

Choose one option:

When dividing a decimal by a whole number, ignore the decimal point at first, perform the division, and then place the decimal back in the correct position. Always estimate to check if your answer is reasonable.

Dividing a Decimal by a Whole Number

Dividing decimals follows the same logic as dividing whole numbers. The key difference is correctly placing the decimal point in the answer. You can think of 4.8 as 48 tenths, which helps visualise why dividing gives 1.6 instead of 16.

Step-by-Step Method

  1. Ignore the decimal point and divide as usual.
  2. Count how many digits were after the decimal in the original number.
  3. After dividing, place the decimal point in your answer so it has the same number of decimal places.
  4. Estimate roughly before or after to confirm your result makes sense.

Worked Examples

Example 1: 3.6 ÷ 4
Ignore the decimal: 36 ÷ 4 = 9 → one decimal place → 0.9.

Example 2: 6.4 ÷ 2
64 ÷ 2 = 32 → one decimal place → 3.2.

Example 3: 9.9 ÷ 3
99 ÷ 3 = 33 → one decimal place → 3.3.

Example 4: 5.25 ÷ 5
525 ÷ 5 = 105 → two decimal places → 1.05.

Common Mistakes

  • Forgetting the decimal position: Always check the number of decimal places in your original number before placing the decimal in your answer.
  • Incorrect estimation: Dividing by more than 1 should make the number smaller, not larger.
  • Dropping zeros: When necessary, add placeholder zeros to complete the division accurately.

Real-Life Applications

Dividing decimals occurs frequently in everyday problems:
• £4.80 split between 3 people → £1.60 each.
• 4.8 metres of ribbon cut into 3 equal parts → 1.6 metres per piece.
• A 4.8-litre bottle filled into 3 smaller bottles → 1.6 litres each.

Understanding decimal division ensures accuracy in money, measurement, and unit-rate problems.

FAQs

1. Why do I move the decimal back?
Because dividing by 10 shifts every digit one place to the right, matching the number of decimal places in the original decimal.

2. Can I use long division?
Yes. Write the numbers as whole numbers (e.g. 48 ÷ 3) and adjust the decimal point at the end.

3. What if the division doesn’t end evenly?
Keep dividing and add zeros after the decimal to get an accurate result.

4. How can I check my answer?
Multiply your result by the divisor — it should give you the original decimal (1.6 × 3 = 4.8).

Study Tip

Practise dividing decimals by writing them as equivalent fractions. For example, 4.8 ÷ 3 = (48 ÷ 3) ÷ 10 = 16 ÷ 10 = 1.6. This visual method reinforces how place value works in division.

Learning to divide decimals confidently makes money, measurement, and ratio problems much simpler in GCSE Maths and beyond.