How_To_Be_Good_At_Math

180 MEASUREMENT • THE VOLUMES OF SOLIDS MEASUREMENT •^ WORKING OUT VOLUME WITH A FORMULA

Look at this sugar cube.

Each side of the cube

is 1cm long, so we call it a

cubic centimetre or 1 cm³.

If each side was

1 mm long, the

volume would be 1 mm³.

If the sides were 1 m

long, it would be 1 m³.

First, let’s fill

The median

of the box. We

can fit 8 cubic

centimetres into

this layer.

The volumes of solids

The volumes of 3D shapes are usually measured using units called cubic

units. Cubic units are based on units of length, and they include cubic

centimetres and cubic metres.

8 cm ³

LENGTH1 cm

Now look

at this

box. We can

work out its

volume by

filling it

with cubic

centimetres.

If we keep

going until

the box is full,

we find the box

holds 24 cubic

centimetres.

In other words,

its volume is

24 cm³.

TRY IT OUT

2D shapes

You can use the method we've just

learned to find the volume of all

sorts of shapes, not just regular

ones. Count the cubic centimetres

to work out the volume of each of

these three shapes.

24 cm³

1 cm ³

LENGTH

4 cm

HEIGHT 3 cm

WIDTH 2 cm

HEIGHT1 cm

WIDTH

1 cm

Answers on page 319

180_181_Volume_of_Solids.indd 180 29/02/2016 18:04