Number worksheet — GCSE Foundation

1.A block of butter has a mass of 250 g, correct to the nearest 10 g. Using m for the mass of the block in grams, write down the error interval for m.

2.A restaurant adds a service charge of 15% to a bill of £120. Work out the service charge.

3.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.

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

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

6.Work out (3 × 10²) × (2 × 10⁵). Give your answer in standard form.

7.A water tank holds 80 litres when full. It currently contains 60 litres. Work out what fraction of the tank is empty.

8.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.

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

10.A recipe uses 160 g of flour. Sam wants to increase the amount by 1/4. Work out the new amount of flour.

11.Round 6.283 to 1 significant figure.

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

13.A van has a mass of 2,000 kg, correct to 1 significant figure. Using m for the mass of the van in kilograms, write down the error interval for m.

14.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.

15.A recipe needs 0.485 kg of flour per cake. A bakery estimates its flour order by rounding this amount to 1 significant figure, then multiplying by the 60 cakes it plans to bake. Work out the bakery's estimate for the total flour needed, in kg.