Volume is the space that something takes up. When we measure the volume of water in a cup, we are measuring how much space the water takes up inside the cup. Capacity is the amount that something can hold. We might need to measure a cup's capacity so that we know how much water it can hold.

Volume

We measure the volumes of solids in cubic units, such as cubic millilitres (mm³), cubic centimetres (cm³) and cubic metres (m³). The ³ tells us that the unit of measurement is cubed, which means we can imagine each unit taking up a cube (one square block) of space at that size.

The imperial system of measurement uses cubic inches (in³), cubic feet (ft³) and cubic yards (yd³).

Liquid volume

When we measure the volume of liquids, we use millilitres (ml), centilitres (cl) and litres (l).

Using imperial measurements, the volumes of liquids are measured in fluid ounces (fl oz). 8 fluid ounces make up one cup. 2 cups make up a pint, while 8 pints make a gallon.

Measuring capacity

We can use the same formula, ​​​​​​​height x width x depth, for measuring capacity.

We need to find out the capacity of a shipping container (how much space there is inside). The height is 2 m, width is 2 m and the depth is 8 m.

​​​​​​​                       2 x 2 x 8 = 32

So the total capacity of the container is 32 m³.

We can write that 3 < 6, which means 3 is less than 6. And we can write that 4 > 1, which means 4 is greater than 1.

If two amounts are the same, we use the equals sign (=). So if cup A and cup B both hold the same amount of water, we can say that ​​​​​the water in cup A = the water in cup B.

Key words

capacity the largest amount that a container can hold

cubic units units of measurement for measuring volume, such as cubic centimetres (cm³) and cubic metres (m³)

formula a set of mathematical instructions to produce a specific result

volume the space that something takes up