Number worksheet — GCSE Higher

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

2.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.

3.A market trader buys 8 melons at £1.35 each. He sells all of them for a total of £15.60. Work out his profit.

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

5.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.

6.A bag of flour is labelled 1.5 kg, correct to the nearest 0.1 kg. The true mass of the flour is m kg. Which inequality gives all the possible values of m?

7.A company sells 4 × 10³ items per day, each priced at £2.50. It operates for 3 × 10² days a year. Work out the company's total revenue for the year. Give your answer in standard form.

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

9.Write these three numbers in order, starting with the smallest: 3/5, 0.55, 58%

10.A digital timer truncates every time to 1 decimal place. It shows a swimmer's time for one length as 12.3 seconds. Using t for the swimmer's actual time in seconds, write down the error interval for t.

11.The thickness of a sheet of card is 0.02384 cm. Write this thickness correct to 2 significant figures.

12.A car manufacturer offers a car in 6 colours and 4 trim levels. Two colour-and-trim combinations are not available: red with sport trim, and white with sport trim. Work out how many different colour-and-trim combinations are available.

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

14.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.

15.Three-digit numbers are made using the digits 2, 3, 4, 6, 8 and 9. No digit may be used twice in the same number. Work out how many of these three-digit numbers are odd.