Phoebe pays 3.4 pence per minute to use her phone. On average Phoebe uses her phone for 74 minutes per day. She pays her phone bill for 24 days. Phoebe works out an estimate by rounding each number to 1 significant figure.
Is Phoebe's estimate an underestimate or an overestimate? Give a reason for your answer.
247 exam-style questions on OCR GCSE Maths Estimating. Each one has a worked solution and a mark scheme showing where the marks go.