Comparing and measuring · Grade 4
In Grade 4 you learn: comparing measures in different units.
Measuring tells us how long, how heavy or how much something holds. First we compare — longer or shorter, heavier or lighter, more or less — and then we measure with rulers, scales and jugs, using units like centimetres, kilograms and millilitres.
Key facts
- Length is how long, tall or wide something is. We measure it in centimetres (cm), metres (m) and kilometres (km).
- Mass is how heavy something is. On a balance, the heavier side goes down. We use grams (g) and kilograms (kg).
- Capacity is how much a container holds. We use millilitres (ml) and litres.
- When you use a ruler, line the end of the object up with 0.
- To read a scale, first work out what each small line is worth.
- 1 m = 100 cm, 1 kg = 1,000 g, 1 litre = 1,000 ml.
Worked examples
Example 1
How long is the pencil?
Answer: 9 cm
Example 2
A jug has 700 ml of water in it. Sam pours out 250 ml. How much water is left?
Answer: 450 ml