Eddie and Ellen use a calculator to work out 431.114.3+3.82\displaystyle \frac{431.1}{14.3 + 3.8^2}14.3+3.82431.1
Eddie's answer is 1.5
Ellen's answer is 15
One of those answers is correct.
Use approximations to find out which answer is correct.
Practise CIE IGCSE Maths Estimating with exam-style questions for Core and Extended tier. 15 questions, matched to the CIE IGCSE Maths (0580) specification and written in Paper 1 and Paper 3 (Core) or Paper 2 and Paper 4 (Extended) style. Every question includes a full worked solution and mark scheme, so you can see where marks are awarded rather than just whether you got the answer right.