Measurements (e.g. units of length and mass, units of money)

In this lesson we will explore the different units used to measure the world around us. 📏⚖️💰

Length is measured in the metric system. The most common units are millimetre (mm), centimetre (cm), metre (m), and kilometre (km).

Analogy: A metre is about the length of a typical school desk. A kilometre is roughly the distance you can walk in 10 minutes at a normal pace.

Mass is also measured in the metric system. Common units are gram (g), kilogram (kg), and tonne (t).

Analogy: A kilogram is roughly the weight of a small backpack. A tonne is the weight of a large car.

In China, money is measured in yuan, jiao, and fen. The hierarchy is:

• 1 yuan = 10 jiao
• 1 jiao = 10 fen
• 1 yuan = 100 fen

Analogy: Think of a yuan as a big coin, jiao as a smaller coin, and fen as a tiny coin.

When converting, remember to multiply or divide by the appropriate factor.

1. To convert from kilometres to metres, multiply by 1000.
2. To convert from grams to kilograms, divide by 1000.
3. To convert from yuan to fen, multiply by 100.

Example: Convert 3 km to metres.

$$3 \text{ km} = 3 \times 1000 \text{ m} = 3000 \text{ m}$$

• Read the question carefully to identify the required unit.
• Show all your conversion steps; partial credit is awarded for correct methodology.
• Use the correct symbols (mm, cm, m, km; g, kg, t; ¥, 角, 分).
• Check your final answer for the correct unit and significant figures.

1. Convert 750 cm to metres.
2. Convert 2.5 t to kilograms.
3. Convert 5 ¥ to fen.
4. If a road is 12 km long, how many metres is it?

Try solving these before checking the answers below.

Answers:

1. 7.5 m
2. 2500 kg
3. 500 fen
4. 12000 m