Which unit fits best?
You learn to estimate which unit fits: mm, cm, m, km, g, kg, ml or l.
How to work it out
- Think of something you know: a bag of sugar is 1 kg.
- Compare: much smaller, about the same, or much larger.
thickness of a coin1 mm
length of an exercise book3 dm
height of a door2 m
Amsterdam – Utrecht36 km
a paperclip1 g
a bag of sugar1 kg
a carton of milk1 l
The height of a door is about 2 …
- Think of a metre: it comes up to about your waist.
- A door is twice as high.
- It is 2 metres.
More examples
The weight of a bag of apples is about 2 …
- Think of a bag of sugar: it weighs a kilogram.
- A bag of apples weighs as much as two bags.
- It is 2 kilograms.
The volume of a teaspoon is about 5 …
- Think of a carton of milk: that is a litre, far too much.
- A teaspoon holds only a few drops.
- It is 5 millilitres.