Measurement
Volume with unit cubes
Find the volume of a box by counting the unit cubes that fill it.
Volume is how much space a solid takes up. The easiest way to measure it is to fill the solid with small cubes that are all the same size — unit cubes — and count them.
Count in layers
Nobody counts the cubes one at a time. Work out how many are in the bottom layer, then multiply by the number of layers, because every layer holds the same amount.
Worked example
How many unit cubes fill a box that is 5 cubes long, 2 cubes wide and 3 cubes tall?
The bottom layer is 5 along and 2 across, so it holds 5 × 2 = 10 cubes.
One layer is a rectangle, and a rectangle of cubes is length times width.
Try it together
Let us fill a box that is 4 cubes long, 3 cubes wide and 2 cubes tall.
One layer first, then all the layers.
1.How many cubes are in one layer of a box 4 cubes long and 3 cubes wide?
Have a go
Have a go on your own: how many unit cubes fill a box 3 cubes long, 3 cubes wide and 2 cubes tall?
Ready to practise?
Eight questions on what you have just read. Nothing is timed, and you can play as many times as you like.