Printable · GCSE Higher · ages 14-16

Limits of accuracy and bounds worksheet — GCSE Higher

Fifteen questions on "limits of accuracy and bounds" — DfE statement N16. Print it, or print three versions so neighbours cannot copy by letter; the key gives the letter for each version.

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Limits of accuracy and bounds worksheet — GCSE Higher

Maths · GCSE Higher · N16 · Limits of accuracy and bounds · 15 questions

MathsUKwww.geekhero.co.uk

1.Leah measures the length of her classroom with a tape measure marked in centimetres. She writes the length down as 7.3157 m. Give a reason why this is not an appropriate degree of accuracy.
(a)The tape can only give the length to the nearest centimetre
(b)A length in metres must be written to 2 decimal places
(c)A length in metres must be rounded to the nearest metre
(d)The tape can only give the length to the nearest millimetre
2.The number of visitors to a museum on Saturday is given as 1,800, correct to the nearest 100. Which of these could not be the actual number of visitors?
(a)1,850
(b)1,799
(c)1,760
(d)1,750
3.A courier's van has a weight limit of 850 kg for its parcels. The driver's display shows the total mass of the parcels loaded as 850 kg, correct to the nearest 5 kg. Decide whether the parcels are definitely within the weight limit.
(a)Yes, the true mass is at least 847.5 kg and at most 850 kg
(b)No, the true mass could be as high as 852.5 kg
(c)Yes, the display reads 850 kg, which is not above the limit
(d)No, 850 kg on the display rounds up to 855 kg
4.A cyclist travels 40 km, correct to the nearest 10 km, in a time of 3 hours, correct to the nearest hour. Work out the maximum possible average speed, in km/h.
(a)14
(b)10
(c)18
(d)12.9
5.A rectangular garden has a length of 12.4 m and a width of 7.5 m, each measured correct to 1 decimal place. Calculate the upper bound for the area of the garden.
(a)93.375
(b)93.9975
(c)92.0075
(d)93
6.The density of a metal is calculated using density = mass ÷ volume. A sample has a mass of 156 g, correct to the nearest gram, and a volume of 12 cm³, correct to the nearest cm³. Work out the minimum possible density, in g/cm³.
(a)13
(b)13.52
(c)12.44
(d)12.52
7.A plank has length a = 12 cm and a second plank has length b = 7 cm, each correct to the nearest centimetre. Work out the upper bound of a + b.
(a)19.5
(b)20
(c)18
(d)21
8.A speed camera measures a car's speed as 34 mph, correct to the nearest mph. Work out the smallest possible actual speed of the car, in mph.
(a)33.5 mph
(b)33 mph
(c)34.5 mph
(d)34 mph
9.Postage on a parcel is calculated as £4.60, correct to the nearest 20p. Which of these could not be the actual cost of the postage?
(a)£4.55
(b)£4.50
(c)£4.65
(d)£4.80
10.Ava measures a metal rod and records its length as 15 cm, correct to the nearest centimetre. Ben measures the same rod and records its length as 14.8 cm, correct to the nearest 0.1 cm. Decide whether both records can be correct, and give a reason for your answer.
(a)No, because 14.8 cm is not the same length as 15 cm
(b)Yes, because 14.8 cm rounds to 15 cm to the nearest cm
(c)No, because 14.8 cm rounds to 14 cm to the nearest cm
(d)Yes, because 14.8 cm rounds to 15.0 cm to 1 decimal place
11.c = 50, correct to the nearest 10. d = 18, correct to the nearest whole number. Work out the upper bound of c − d.
(a)37.5
(b)27.5
(c)36.5
(d)26.5
12.A lift has a safe working load of 500 kg. Four people get in the lift and the lift's display records their total mass as 493 kg, correct to the nearest kg. Decide whether the four people are definitely within the safe working load.
(a)No — 493 kg is only an estimate, so it may be over 500 kg
(b)Cannot be decided without the exact total
(c)Yes — the greatest possible total is 493.5 kg, under 500 kg
(d)No — the true total could be as high as 498 kg
13.p = 24 and q = 6, each correct to the nearest integer. Work out the greatest degree of accuracy to which p ÷ q can be guaranteed correct.
(a)the nearest whole number
(b)it cannot be given to any degree of accuracy
(c)the nearest 0.1
(d)the nearest 10
14.A rope is measured as 15 m, correct to the nearest metre. Write down the error interval for the true length, l, of the rope.
(a)14.5 < l < 15.5
(b)14.5 ≤ l < 15.5
(c)14 ≤ l < 16
(d)14.5 ≤ l ≤ 15.5
15.A machine fills bags of sugar and shows the mass of each bag to the nearest 10 g. A checker rejects any bag whose actual mass is less than 996 g. One bag shows a mass of 1,000 g on the machine. Decide whether this bag could be rejected, and give a reason for your answer.
(a)No — the actual mass is exactly 1,000 g
(b)Yes — the actual mass could be as low as 995 g
(c)Yes — the actual mass could be as low as 990 g
(d)No — the actual mass is at least 999.5 g

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