Level 5-6 Numbers - Approximating

In KS3 Maths you'll have to work out some problems involving large numbers. Before you work them out it's a good idea to have some idea of what the answer will be. That's where approximations come in.

Approximations give you a rough idea what the result of a calculation will be. Though you still have to work them out, the numbers involved are much easier to deal with as they end in zeros. Approximations are made by rounding numbers up or down to the nearest 10, 100 or even 1,000. Say you are asked to multiply 87 x 23. That would be hard but if you round the figures up/down it becomes simpler: 90 x 20 = 1,800. This answer is of course wrong, but it is quite close to the actual answer you want: 87 x 23 = 2,001. It is useful to approximate the answer to calculations so that you can check if your answers are correct.

Test your knowledge of approximating in the following quiz. Take your time and read each question carefully. Good luck!