GCSE Maths Practice: decimals

Question 3 of 10

This question develops Higher GCSE fluency with multi-step decimal arithmetic — subtraction, division, and rounding to two decimal places.

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\( \begin{array}{l} \textbf{Calculate } (6.15 - 3.75) \div 0.488,\\ \textbf{giving your answer to 2 decimal places.} \end{array} \)

Choose one option:

Estimate first — (6 − 4) ÷ 0.5 ≈ 4, so an answer near 5 is expected. This checks your decimal placement.

This Higher-tier decimals problem combines subtraction, division, and rounding — demanding precision across each stage.

Step-by-step reasoning

  1. Subtract: 6.15 − 3.75 = 2.40 (align decimals before subtracting).
  2. Remove decimals for division: 2.40 ÷ 0.488 = 2400 ÷ 488.
  3. Divide accurately: 488 × 5 = 2440 (slightly too high), so answer ≈ 4.9.
  4. Round to 2 d.p.: 4.918 → 4.92.

Worked Examples

Example 1: (5.4 − 1.2) ÷ 0.8
→ 4.2 ÷ 0.8 = 5.25.

Example 2: (8.25 − 4.75) ÷ 0.7
→ 3.5 ÷ 0.7 = 5.0.

Example 3: (2.5 − 0.95) ÷ 0.31
→ 1.55 ÷ 0.31 ≈ 5.00.

Common Pitfalls

  • Not aligning decimals when subtracting.
  • Forgetting to move the decimal in both numbers during division.
  • Rounding too early — always round at the end.

Extension Task

Repeat the calculation with the divisor changed to 0.5. How does halving the divisor affect the result?

Estimation Check

6.15 − 3.75 ≈ 2.4 and 2.4 ÷ 0.5 ≈ 4.8, confirming the final result 4.92 is reasonable.

Exam Tip

In multi-step decimal questions, clearly label each stage — missing one line of working often costs method marks.