 # 11.01 Volume using unit cubes

Lesson

## Ideas

We have counted squares to  find the area of a shape  and can use that to help us find the volume in this lesson. Let's try this problem to review.

### Examples

#### Example 1

Find the area of the shape below.

Worked Solution
Create a strategy

Count the total number of squares.

Apply the idea

There are 5 squares inside the shape.

\text{ Area }= 5\, \text{units}^2

Idea summary

To find the amount of space a shape takes up, we can use unit squares.

## Volume with unit cubes

This video introduces the unit cube and how it can be used to measure volume (space an object takes up).

### Examples

#### Example 2

In this figure, 1\text{ block}=1\text{ cm}^3. What is the volume of the solid figure?

Worked Solution
Create a strategy

Count the total number of blocks.

Apply the idea

There are 10 blocks in the solid.

\text{Volume}=10\text{ cm}^3

Idea summary

Volume means the amount of space a 3D shape takes up.

To find the volume we can count the number of unit squares that fit inside the shape.

## Volume with arrays

What if you cannot see all the blocks? Can we still work out the volume?

### Examples

#### Example 3

In this figure, 1\text{ block}=1\text{ cm}^3. What is the volume of the solid figure?

Worked Solution
Create a strategy

Multiply the columns by the rows of the array then multiply the answer with the number of sets the solid figure has.

Apply the idea

We can see on the figure that the front face is an array of blocks with 4 rows and 3 columns. We have 2 sets of this face.

Idea summary

A cubic millimetre (\text{mm}^3) is about as big as a grain of sand.

A cubic centimetre (\text{cm}^3) is about as big as the end of your thumb.

A cubic metre (\text{m}^3) is about as big as a washing machine.