Number worksheet — GCSE Foundation

1.A red blood cell has a diameter of about 7 × 10⁻⁶ metres. A virus has a diameter about 100 times smaller. Work out the diameter of the virus. Give your answer in standard form.

2.A plane flies 2340 km at an average speed of 780 km/h. It departs at 08:20. Work out the arrival time, using the 24-hour clock.

3.To estimate the cost of buying 38.7 m of rope at £21.40 per metre, both numbers are first rounded to 1 significant figure. Work out the estimate.

4.A cyclist rides at a steady speed of 8 metres per second. Work out this speed in kilometres per hour.

5.Which of these is written correctly in standard form?

6.3.4 × 10⁵ is written as an ordinary number. Work out this number.

7.A café sells ice cream in three flavours: vanilla, mango and pistachio. Isla buys a cone with two scoops, using two different flavours, one for the bottom scoop and one for the top scoop. Work out how many different cones she could buy.

8.A charity raises 8 × 10⁶ pounds. This total is shared equally among 2 × 10² local projects. Work out how much each project receives, in standard form.

9.Write 0.0038 in standard form.

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

11.Work out 10% of 30% of £200.

12.The diameter of an artificial silk fibre is 4 × 10⁻⁶ metres. One nanometre is 10⁻⁹ metres. Work out the diameter of the fibre in nanometres.

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

14.A number, n, is equal to 3.7 when rounded to 1 decimal place. Write down the error interval for n.

15.A train journey takes 45 minutes, correct to the nearest 5 minutes. Using t for the actual time of the journey in minutes, write down the error interval for t.