Calculating Volume - Cycle 2

| Mathematics

How is Volume Calculated?

The volume of a solid can be found by counting unit cubes and half unit cubes.

Important!

Two half-cubes form a whole unit cube.

Exemples de demi-cubes

Rule

Follow these steps to calculate the volume of a solid.

  1. If there are half cubes, join them to form whole unit cubes.
  2. Count the total number of unit cubes, including those formed using the half cubes.
Be careful!

Remember to include the unit cubes that are not visible.

Example:

When looking at this image, I only see 4 unit cubes.

Exemple d’un solide dont un cube-unité n’est pas visible-1

Another cube unit is placed under unit cube 1. It is visible when looking at the solid from the following perspective.
Exemple d’un solide dont un cube-unité n’est pas visible -2

Example

What is the volume of the following solid?

 Exemple du calcul du volume-1

  1. If there are half cubes, I join them to form whole unit cubes.

    I form 1 unit cube using 2 half cubes.

Exemple du calcul du volume-2
  1. I count the total number of unit cubes, including those formed using the half cubes.

Exemple du calcul du volume-3

The volume of this solid is 7 cubic units.

Find out more!

If a solid has an odd number of half cubes, calculate the volume of the figure in terms of half cubes. To do this, divide each unit cube into two half cubes.

Example: The volume of this solid is 13 half-cubic units.

Exemple d’un solide dont le volume est calculé avec des demi-cubes

Calculating Volume Using Unit Cubes

Calculating Volume Using Unit Cubes