Measurement

Measuring answers the questions "how long?", "how big?", "how heavy?" and "how long does it take?" with a number and a unit. This ladder starts with hands and feet as rulers, climbs through perimeter, area and volume, and ends with the questions scientists and engineers ask: how things change when you scale them up, how to keep units straight, and how accurate a measurement really is.

Step	Page	You will be able to
Play	Measuring with your body, and how big is Mars?	Compare and measure with hand spans and paces, and picture the sizes of Earth, the Moon and Mars
Explore	Units, conversions and perimeter	Use metres, grams, litres and seconds, convert between units, and find the perimeter of a shape
Build	Area	Find the area of rectangles, triangles, parallelograms, trapezoids, circles and shapes made of them
Master	Volume and surface area	Find the volume and surface area of prisms, cylinders, cones and spheres, and convert to litres
Beyond	Scale, units and accuracy	Use scale drawings, see why area and volume grow faster than length, check work with units, and give honest error bounds