Number worksheet — GCSE Higher

1.Which of these numbers rounds to 0.048 when rounded to 2 significant figures?

2.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.

3.A flight departs at 21:35 and lands at 06:10 the following morning. Work out the total flight time.

4.A number, y, is equal to 8.2 when rounded to 1 decimal place. Write down the error interval for y.

5.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.

6.A plank of wood is 5 1/4 m long. Pieces of length 3/4 m are cut from it. Work out how many complete pieces of 3/4 m can be cut from the plank.

7.A recipe uses 0.625 kg of flour. Write this mass as a fraction of a kilogram, in its simplest form.

8.A cube-shaped storage tank has a volume of 15,625 cubic centimetres. Work out the length of one edge of the tank.

9.A washing machine costs £320 before VAT. VAT is charged at 20%. Work out the total price including VAT.

10.2/3 of an amount of money is £30. Work out the amount.

11.A crowd of 8,400 people is recorded correct to the nearest 100. Work out the smallest possible number of people in the crowd.

12.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.

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

14.By listing systematically, work out how many two-digit multiples of 5 can be made using the digits 0, 3 and 5, if each digit can be used at most once and the number cannot start with 0.

15.Work out (5 × 10⁴) ÷ (2 × 10⁻²). Give your answer in standard form.