Length, Mass and Capacity
Metric and imperial units to measure size, weight and volume.
Key idea
Metric and imperial units to measure size, weight and volume.
In depth
Metric units are linked by powers of ten: kilo (1000), centi (1/100), milli (1/1000). Length is measured in metres, mass in grams, capacity in litres. Pick a unit that makes numbers manageable.
Worked example
2.4 kg = 2400 g; 350 mL = 0.35 L; 1.2 m = 120 cm.
Real-world uses
- Measuring furniture for a new room
- Checking parcel weights
- Filling a fish tank to the right level
Common mistake
Mixing capacity and volume or mass and weight in everyday contexts. Be careful with units.
How to learn this
- Read the key idea and say it in your own words.
- Work through the worked example, then try a similar problem.
- Use the interactive lesson’s visual and mini-quiz to check the pattern.
Frequently asked questions
What is Length, Mass and Capacity?
Metric and imperial units to measure size, weight and volume. It is a topic at the beginner level in Arithmetic & Number Sense.
Where is Length, Mass and Capacity used in real life?
Real-world examples: Measuring furniture for a new room; Checking parcel weights; Filling a fish tank to the right level.
What should I learn before Length, Mass and Capacity?
Make sure you are comfortable with Unit Conversion, the previous topic in Arithmetic & Number Sense.
What is a common mistake with Length, Mass and Capacity?
Mixing capacity and volume or mass and weight in everyday contexts. Be careful with units.
How can I practise Length, Mass and Capacity?
Open the interactive lesson, play with the visual, then answer the three-question mini-quiz. Getting two right marks the topic complete.
What comes after Length, Mass and Capacity?
Move on to Time and Clocks next.
Related beginner topics in Arithmetic & Number Sense
- Counting & Cardinality – Assigning one number word to each object to find how many there are.
- Place Value – The value of a digit depends on its position: ones, tens, hundreds and so on.
- Number Line – A line where numbers are placed in order at equal spacing to compare and add them.
- Comparing Numbers – Use <, > and = to say which number is smaller, larger or equal.
- Ordering Numbers – Arranging numbers from least to greatest or the reverse.
- Even and Odd Numbers – Even numbers divide by 2 with no remainder; odd numbers leave remainder 1.