The circumference is the perimeter of a circle. It is a length and so is measured in \(mm\), \(cm\), \(m\) or \(km\). An area is measured in square units: \(mm^{2 ...

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.

Space to play or pause, M to mute, left and right arrows to seek, up and down arrows for volume. Using cushions to build a fort, explore the concept of finding the largest area for a fixed perimeter.