Number worksheet — GCSE Foundation

1.Work out (8 × 10⁻⁵) × (5 × 10³). Give your answer in standard form.

2.A photograph uses 4 × 10⁶ bytes of storage. A memory card holds 3.2 × 10¹⁰ bytes. Work out how many of these photographs the card can hold. Give your answer in standard form.

3.Write these fractions in order, starting with the smallest: 2/3, 3/5, 5/6, 1/2

4.A charity raises money from a raffle and a cake sale in the ratio 5 : 3. Altogether the charity raises £320. Work out how much money the cake sale raised.

5.A quantity surveyor calculates a length as 24.6851 m. Round this length to 2 decimal places.

6.Rice is sold in a 400 g bag for £1.12 and in a 1.5 kg bag for £3.90. Work out how much less the rice in the larger bag costs per kilogram.

7.A café is planning its lunch menu. It will offer one soup from 3 choices and one sandwich from 4 choices, but the mushroom soup, one of the 3 soups, will only be served with the cheese sandwich, one of the 4 sandwiches, on a normal day. Work out how many different soup-and-sandwich combinations are available on a normal day.

8.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.

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

10.A jumper is reduced by 15% in a sale to a price of £42.50. Work out the original price.

11.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.

12.A café buys 18 boxes of teabags at £3.45 each, and sells all the teabags for £108 in total. Work out the café's profit.

13.A jacket normally costs £65. In a sale it is reduced by 20%, and the shop then takes a further £5 off at the till. Work out the final price.

14.The density of a type of plastic is 0.9 g/cm³. Work out this density in kg/m³.

15.The number of pages in a book is 240, correct to the nearest 10 pages. Write down the error interval for the actual number of pages, n.