The circumference of a circle is the distance around the shape. The ability to round a number to a number of decimal places or to a number of significant figures means that answers can be written to ...

Archimedes' method finds an approximation of pi by determining the length of the perimeter of a polygon inscribed within a circle (which is less than the circumference of the circle) and the perimeter ...

The ability to round a number to a number of decimal places or to a number of significant figures is essential if answers are to be written to the correct degree of accuracy asked for in a question.