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S3 Maths: Significant Figures and Percentage Error (Paper 2 (intermediate))
S3 Maths: Significant Figures and Percentage Error (Paper 2 (intermediate))
Paper 2 (intermediate): ten questions on significant figures and percentage error, with answers and one line notes.
01 Paper details (check answers afterwards)
| Item | Detail |
|---|---|
| Questions | 10 |
| Suggested time | 20 |
| Difficulty mix | Foundation 3 · Intermediate 3 · Challenge 3 · Error redo 1 |
| Chapter | Chapter: S3 Maths: Significant Figures and Percentage Error |
| Level | S3 |
02 Questions (10 items)
- FoundationRound 299.6 to three significant figures.
- FoundationRound 0.007 to one significant figure.
- FoundationA bag of sugar measures 4.5 kg to the nearest 0.1 kg. What is the maximum absolute error?
- IntermediateA class has a true size of 80 but is counted as 78. Find the percentage error.
- IntermediateA rope measures 12 cm to the nearest 1 cm. State its lower and upper limits.
- IntermediateWork out 2.4 times 3.6 and give the answer to two significant figures.
- ChallengeA measurement has a percentage error of 5 per cent and a true value of 60. Find the maximum absolute error.
- ChallengeA measurement has a relative error of 0.02. Write it as a percentage error.
- ChallengeA bag of rice measures 250 g to the nearest 10 g. Find the maximum absolute error and the percentage error.
- Error redoError clinic: a student claims every zero is a significant figure. What is wrong?
03 Answers and one-line notes
| # | Answer | One-line note |
|---|---|---|
| 1 | 300 | The third significant figure is 9 and the next digit 9 rounds it up so 299 becomes 300. |
| 2 | 0.007 | The only non-zero digit 7 is already the first significant figure, so the value stays the same. |
| 3 | 0.05 kg | The smallest division is 0.1 kg and half of that is 0.05 kg. |
| 4 | 2.5% | The absolute error is 2, and 2 divided by 80 times one hundred per cent gives 2.5 per cent. |
| 5 | Lower limit 11.5 cm, upper limit 12.5 cm | Add and subtract half a division, 0.5, to get the limits 11.5 and 12.5. |
| 6 | 8.6 | The product is 8.64 and both factors have two significant figures, so the answer rounds to 8.6. |
| 7 | 3 | Five per cent of 60 is 3, so the maximum absolute error is 3. |
| 8 | 2% | Multiplying 0.02 by one hundred per cent gives 2 per cent. |
| 9 | Maximum absolute error 5 g, percentage error 2 per cent | Half of 10 g is 5 g, and 5 divided by 250 times one hundred per cent is 2 per cent. |
| 10 | Leading zeros are not significant | In 0.0456 the two leading zeros only mark place value; only zeros between digits or trailing after a decimal point count. |
04 What to do after marking
- After marking, redo only the wrong items and write down which step went wrong (formula, unit, or misread number).
- Repeat the same item two days later; move to the next paper only when both attempts are correct.
- Parents only need the answer and note columns; there is no need to explain every item.
Ask first whether a zero counts: zeros between non-zero digits, or trailing zeros after a decimal point, do count, while leading zeros that only mark place value do not. For error questions, write the maximum absolute error as half the smallest scale division, then divide by the true value and multiply by one hundred per cent.Tutor Registration →
Questions and answers are written originally by the TutorZone team and are not taken from any school, publisher or examination authority paper. Every value is checked by computer.
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