iGCSE Mathematics (0580) - C1.10 Limits of accuracy- Exam Style Questions Paper 1- New Syllabus
Question
The height, \(h \text{ cm}\), of a door is \(180 \text{ cm}\), correct to the nearest centimetre.
Complete this statement about the value of \(h\).
Most-appropriate topic codes (Cambridge IGCSE Mathematics 0580):
▶️ Answer/Explanation
The measurement is correct to the nearest \(1 \text{ cm}\).
To find the bounds, halve the degree of accuracy: \(1 \div 2 = 0.5 \text{ cm}\).
Lower bound: \(180 – 0.5 = 179.5\).
Upper bound: \(180 + 0.5 = 180.5\).
✅ Answer: \(179.5 \le h < 180.5\)
Question
The height, $h$ metres, of a building is 635 m, correct to the nearest metre.
Complete this statement about the value of $h$:
____ $\le h <$ ____
Most-appropriate topic codes (Cambridge IGCSE Mathematics 0580):
▶️ Answer/Explanation
✅ Answer: $634.5 \le h < 635.5$
(a) Tanvi rounds the number 4896. She writes down 4900. Rahul says Tanvi rounded 4896 correct to the nearest 100. Explain why Rahul cannot be certain that Tanvi rounded 4896 correct to the nearest 100.
(b) Calculate \(\frac{6.4\times 4^{2}}{17.9-6.1}\). Give your answer correct to 3 decimal places.
▶️ Answer/Explanation
(a) 4900 could result from rounding to different place values (e.g., nearest 10 or 100). Since 4896 rounds to 4900 in both cases, Rahul can’t be certain which method Tanvi used.
(b) Solution steps:
- Calculate numerator: 6.4 × 4² = 6.4 × 16 = 102.4
- Calculate denominator: 17.9 – 6.1 = 11.8
- Divide: 102.4 ÷ 11.8 ≈ 8.678 (to 3 decimal places)
Final answer: 8.678
