Number worksheet — GCSE Foundation

1.A spreadsheet shows that 812 − 397 = 315. Work out an estimate for 812 − 397, by rounding each number to the nearest 100, to check whether the spreadsheet's answer is reasonable.

2.Light travels at 3 × 10⁸ metres per second. Work out how far light travels in 2 × 10⁻⁶ seconds. Give your answer in standard form.

3.A cinema has 250 seats. 12% of the seats are reserved. Work out how many of the seats are reserved.

4.Round 4,685 to the nearest 100.

5.Write 45,000 in standard form.

6.Light travels at 2.998 × 10⁸ metres per second. A distant object in space is 3.1 × 10¹⁵ metres from Earth. Work out an estimate for the number of seconds light takes to travel from the object to Earth, by rounding each number to 1 significant figure.

7.At midday the temperature in the Lake District was 3 °C. By midnight it had fallen to −6 °C. Work out the fall in temperature.

8.A plumber charges a call-out fee of £45 and then £28 for each hour she works. She is at a house from 09:15 until 12:45. Work out the total charge.

9.Petrol costs £1.48 per litre. Sam buys 35 litres and pays with three £20 notes. Work out his change.

10.A shortbread recipe uses flour and butter in the ratio 5 : 2. Yuki changes the recipe by doubling the amount of butter but keeping the amount of flour the same. Work out the fraction of the new mixture that is butter.

11.A coach journey has a 55 minute first leg, a 20 minute break and a 40 minute second leg. The coach leaves at 13:25. Work out the arrival time, using the 24-hour clock.

12.Round 0.006852 to 2 significant figures.

13.Hannah works out 3.1 × 19.6 on her calculator and writes down 6.076. Work out an estimate for 3.1 × 19.6, by rounding each number to 1 significant figure.

14.Work out 2⁵.

15.A country's population is 8,340,000, and it is estimated that 1,950,000 of them live in the capital city. By rounding each number to 1 significant figure, work out an estimate for the number of people who do not live in the capital city.