Units and conversions · Year 4
In Year 4 you learn: converting km, m, cm and mm.
Metric units are built on 10, 100 and 1,000, so converting between them is just multiplying or dividing. Some countries also use imperial units like miles, pounds and gallons, which convert with approximate rates. Area and volume units need extra care.
Key facts
- Length: 10 mm = 1 cm, 100 cm = 1 m, 1,000 m = 1 km.
- Mass: 1,000 g = 1 kg, 1,000 kg = 1 tonne. Capacity: 1,000 ml = 1 litre.
- Big unit → small unit: multiply. Small unit → big unit: divide.
Worked examples
Example 1
Change 3.75 km into metres.
Answer: 3,750 m
Example 2
A bag holds 1.2 kg of flour and another holds 450 g of sugar. What is the total mass in grams?
Answer: 1,650 g