Mathematics for IGCSE & O level - Estimation (Section 3 - No. 15)
Which of the following are important when estimating answers to problems?
Rounding numbers to a suitable level of accuracy.
Using a calculator for every step.
Understanding the context of the problem.
Expressing answers with an appropriate degree of accuracy.
Explication
All options except using a calculator for every step are important. The question is about estimating.