Volume · Usually met around P5
Volume by counting cubes
Cubes in a layer × layers.
How to do it
Method
Cubes in a layer × layers
4 × 3 a layer, 2 layers: 24 cm³
Another way
Column by column
3 + 2 + 1 + 2 + 1 + 1 = 10
In full
Volume is how much space something takes up. A cube with 1 cm sides has a volume of 1 cubic centimetre (1 cm³). A solid built of 1 cm³ cubes has as many cubic centimetres as it has cubes. Way 1: count a layer at a time: a cuboid with 4 × 3 cubes in a layer and 2 layers has 4 × 3 × 2 = 24. Way 2: count column by column: each column has as many cubes as it is tall; add the columns. To compare two solids' volumes, compare their cube counts; different shapes can have the same volume.
Worked examples
Have a go first, then open each one for the answer and the working.
Example 1
The cuboid is built of 1 cm³ cubes. What is its volume in cm³?
Show the answer and working
Answer: 10 cm³
5 × 2 = 10 a layer, 1 layers: 10 × 1 = 10.
Example 2
The solid is built of 1 cm³ cubes (every column stands on the ground). What is its volume in cm³?
Show the answer and working
Answer: 15 cm³
Column by column: back 5 + 3 + 1, front 3 + 2 + 1: 15 cubes.
Example 3
The cuboid is built of 1 cm³ cubes and has a volume of 18 cm³.
True or false?
Show the answer and working
Answer: True
Don't count only the front: 3 × 3 a layer, 2 layers, 18 in all.
Practise it in the game →Volume · Free to start, unlimited questions, no download