We need to fully understand the conventions for rounding numbers to a certain number of significant figures and for rounding to a certain number of decimal places. There are times when we will need to round to one or the other of these. In our final iGCSE exam we are required to round all answers to 3 significant figures, except for angles in degrees, which we should round to one decimal place.

Let’s practice rounding under these two conventions for various numbers.

Exercise

Let’s complete exercise 41 to 43 from pages 119 to 120 of the core textbook:

The answers are below: