Extended: Limits of accuracy: past paper questions

Real questions on extended: limits of accuracy

The newest 15 of 15 written questions. Open one to see it on the real paper.

1. 0980/11 · October/November 2024 · Q17[2]
   17 A distance, $d$ metres, measures 34.6 m, correct to the nearest 0.1 m. Complete this statement about the value of $d$. $⩽d<$See it on the paper →
2. 0980/12 · May/June 2024 · Q22[2]
   22 The length, $l$ metres, of a piece of material is 4.5 m, correct to the nearest 10 cm. Complete this statement about the value of $l$. $\cdots \le l<\dots$See it on the paper →
3. 0980/42 · May/June 2024 · Q1e[3]
   (e) [Diagram: A bottle standing on a lower shelf with a higher shelf above it. The distance from the top of the bottle to the upper shelf is labelled $d$ cm. The height of the bottle is labelled $18.5$ cm. The total distance between the shelves is labelled $23$ cm. The text "NOT TO SCALE" is present.] The bottles of j...See it on the paper →
4. 0980/21 · October/November 2023 · Q16[3]
   16 $P=2w+2h$ $w=11$ and $h=9.5$, both correct to 2 significant figures. Find the lower bound and the upper bound for $P$.See it on the paper →
5. 0980/21 · October/November 2022 · Q24[2]
   24 Violet and Wilfred recorded their times to run $200$ m, correct to the nearest second. Violet took $36$ seconds and Wilfred took $39$ seconds. Work out the upper bound of the difference between their times.See it on the paper →
6. 0980/31 · October/November 2022 · Q5b(i)[2]
   (b) Carlotta buys a bicycle. (i) The length, $l$ cm, of the bicycle is 96 cm, correct to the nearest centimetre. Complete this statement about the value of $l$. $\le l<$See it on the paper →
7. 0980/12 · May/June 2022 · Q18[2]
   18 By writing each number in the calculation correct to 1 significant figure, find an estimate for the value of $\frac{27-2.3^2}{845.4\times 0.048}$ .See it on the paper →
8. 0980/12 · May/June 2022 · Q19[2]
   19 The length, $l$ metres, of a piece of rope is $30.7$ m, correct to 1 decimal place. Complete this statement about the value of $l$ \dots \le l < \dotsSee it on the paper →
9. 0980/42 · May/June 2022 · Q6d(i)[3]
   (d) At a football match, there are 29 800 people, correct to the nearest 100. (i) At the end of the football match, the people leave at a rate of 400 people per minute, correct to the nearest 50 people. Calculate the lower bound for the number of minutes it takes for all the people to leave.See it on the paper →
10. 0980/42 · May/June 2022 · Q6d(ii)[2]
    (d) At a football match, there are 29 800 people, correct to the nearest 100. (ii) At a cricket match there are 27 500 people, correct to the nearest 100. Calculate the upper bound for the difference between the number of people at the football match and at the cricket match.See it on the paper →
11. 0980/31 · October/November 2021 · Q3e[2]
    360 people go on a school trip to one of four places. Some of the information is shown in the table. | | Adventure park | Botanic gardens | Wildlife centre | Red castle | Total | |---|---|---|---|---|---| | Boys | 65 | 12 | | 36 | | | Girls | | 9 | 62 | | 163 | | Staff | 15 | 3 | | | 37 | | Total | 144 | 24 | 121 | 71...See it on the paper →
12. 0980/41 · October/November 2021 · Q2c[4]
    Bob, Chao and Mei take part in a run for charity. (c) When running, Chao has a stride length of $70\text{ cm}$, correct to the nearest $5\text{ cm}$. Chao runs a distance of $11.2\text{ km}$, correct to the nearest $0.1\text{ km}$. Work out the minimum number of strides that Chao could take to complete this dista...See it on the paper →
13. 0980/12 · May/June 2020 · Q13[2]
    13 The height, $h$ metres, of a tower is $76.3$ m, correct to 1 decimal place. Complete this statement about the value of $h$. $⩽h<$See it on the paper →
14. 0980/22 · May/June 2020 · Q15[1]
    15 Ella's height is $175$ cm, correct to the nearest $5$ cm. Write down the upper bound of Ella's height. ................................................ cm [1]See it on the paper →
15. 0980/42 · May/June 2019 · Q1e[2]
    (e) Every page of the newspaper is a rectangle measuring $43\text{ cm}$ by $28\text{ cm}$, both correct to the nearest centimetre. Calculate the upper bound of the area of a page.See it on the paper →

What examiners said

The question of bounds was complicated since the length, l, was in metres while the accuracy was in centimetres, resulting in the question being found challenging. Working in centimetres, but not reverting back to metres for the answer did gain 1 mark, as did the often seen correct values but the wrong way round.

— Examiner report, May/June 2024, 0980/12 Q22 (Cambridge)

Many struggled with this question and especially with upper and lower bound of 9.5 ± 0.05 as they used 9.5 ± 0.5, but they usually showed 11 ± 0.5. Some others first attempted 2 × 11 + 2 × 9.5 was worked out to 41 and then 0.5 added and subtracted to give 40.5 and 41.5.

— Examiner report, October/November 2023, 0980/21 Q16 (Cambridge)

There was a good proportion of correct answers, but error bounds continue to be misunderstood by many candidates. The most common misconception was to find the difference between the two numbers and then apply the bound by adding 0.5 to the answer. Many did understand that the bound should be applied before any calculation and were awarded one mark for giving a value with a bound correctly applied...

— Examiner report, October/November 2022, 0980/21 Q24 (Cambridge)