The important thing to remember about volume is that it has 3 dimensions. Objects extend in 3 different directions in space. So a cuboid that has a width of 5cm, a length of 10cm and a height of 2cm will have volume of 5 x 10 x 2 = 100cm².

The metric units of measurement for volume are “millimetres cubed”, “centimetres cubed” and “metres cubed”. We also need to know the related measures of capacity (i.e. how much liquid or gas something can hold) “millilitres” and “litres”.

• An object with a volume of 1cm³ has a capacity of 1ml
• An object with a volume of 1000cm³ has a capacity of 1l.

Of course, because of the extra dimension, the conversion rates are much bigger with volume, such that:

• 1000mm³= 1cm³;
• 1,000,000cm³= 1m³ (= 1000 l )

Exercise

Let’s complete exercise 5D on page 76 of the textbook:

The answers are below: