Mathematics 0580 · IGCSE · The four operations

The four operations — practice question

Tim uses a technique for multiplying a number by 99. He demonstrates it with $53 \times 99$: $53 \times 99 = 53 \times 100 - 53 = 5300 - 53 = 5247$.

(main)[2]

Find $85 \times 99$ by using Tim’s method.

Worked solution & mark scheme

This 2-mark question has a full step-by-step worked solution and mark scheme. One marking point: “Use $85\times100-85$.” …