GEOMETRY

Volume Of Cuboids

Learn the reliable method for volume of cuboids, then apply it to 11+ exam-style questions.

1 · WHAT YOU NEED TO KNOW

The idea

Volume Of Cuboids questions require you to use properties and labels, not the apparent size of a drawing.

Picture itBuild the solid from unit cubes
2 · THE METHOD

Follow these steps

  1. Mark the information given on the diagram.
  2. Choose the relevant property or formula.
  3. Calculate one step at a time and include units.
3 · WORKED EXAMPLES

See the method in action

Example 1

The diagram shows a cuboid with volume 5120 cm³, length 16 cm and width 20 cm. What is its height?

length 16 cm; width 20 cm; height ?
  1. The base area is 16 × 20 = 320 cm².
  2. Height = 5120 ÷ 320 = 16 cm.
Answer: 16 cm
Example 2

The diagram represents a cuboid holding 125 identical cubes. Each complete horizontal layer contains 25 cubes. How many layers are there?

25 cm × 25 cm × 25 cm
  1. Divide the total by the number in each layer: 125 ÷ 25 = 5 layers.
  2. Check: 25 × 5 = 125 cubes, which reconstructs the stated total.
Answer: 5
4 · ELEVENSPRINT TIP

A useful shortcut

Never rely on a diagram being drawn to scale unless the question says it is.

5 · COMMON MISTAKES

Watch out for these

Using a remembered number without checking the shape

Name the shape or angle rule before substituting values.

6 · TRY IT YOURSELF

Three fresh questions

Ready to check the method? You will get three fresh, validated questions.