Mathematics for IGCSE & O level - Estimation (Section 3 - No. 46)
What are the steps to estimate the result of a calculation, rounding to 1 significant figure?
Round each number to the nearest whole number, then perform the calculation.
Round each number to 1 significant figure, then perform the calculation.
Use a calculator and record all the digits displayed.
Round each number to 2 significant figures and perform the calculation.
Explication
To estimate, round all the numbers involved to 1 significant figure, then perform the calculations.