A metre is a unit used to measure the length of big things, like a whale can be 60 metres (or 60m) long. 1m is equal to 100 centimetres (or 100cm) and you need 1000m to make 1 kilometre (1km).

 

A millilitre is a unit used to measure small amounts of liquid. For example, a teaspoon can hold 5 millilitres (or 5ml) of liquid. You need 1000ml to make 1 litre (1l).

 

A millimetre is a unit used to measure the length of tiny things, like an ant, which can be 6 millimetres (or 6mm) long. You need 10mm to make 1 centimetre (1cm).

 
Multiplication is a short way of working out lots of addition. If I wanted to work out 12 lots of 2, I could add lots of 2's together (which would be 2+2+2+2+2+2+2+2+2+2+2+2 - I'm falling asleep adding all this up!) or I could just say "Well, 2 x 12 = 24. I know that."