Mathematics — Measurement

Subtopic: Capacity (for age ~10)

Learning goals:

  • Know what capacity means.
  • Name common units: litre (L) and millilitre (mL).
  • Convert between litres and millilitres.
  • Use everyday examples from Kenya (jerrycan, water bottle, cup).

What is capacity?

Capacity is how much a container can hold — usually a liquid like water or milk. It is different from mass (weight). We measure capacity in litres and millilitres.

Units you must know

  • 1 litre = 1 L
  • 1 millilitre = 1 mL
  • 1 L = 1000 mL
Quick conversions

- 500 mL = 0.5 L    |    250 mL = 0.25 L    |    1500 mL = 1.5 L

Common containers (Kenyan examples)

  • Small sachet or medicine cup ≈ 5–20 mL
  • Tea cup ≈ 200–250 mL
  • Small water bottle ≈ 500 mL
  • Large soda bottle ≈ 1–2 L
  • Milk tin / jerrycan used at home ≈ 10 L or 20 L

Visual idea: compare fills

1 litre (1 L)
1000 mL
A large soda bottle or 5 small cups
500 mL
500 mL
Half of 1 L — a small water bottle
250 mL
250 mL
A cup used when drinking tea

Tools used to measure capacity

  • Measuring jug — has marks for mL and L.
  • Measuring cylinder — used in science for exact values.
  • Bucket or jerrycan — for large amounts (10 L, 20 L).

Worked examples

Example 1: A jerrycan has 20 L of water. How many 2 L bottles can you fill?

Work: 20 L ÷ 2 L = 10 bottles.

Example 2: Convert 750 mL to litres.

Work: 750 mL ÷ 1000 = 0.75 L. So 750 mL = 0.75 L.

Practice questions

  1. How many millilitres are in 3 litres?
  2. A small bottle holds 250 mL. How many such bottles fill 1.5 L?
  3. A cooking pot holds 4 L. How many 500 mL cups can you fill from it?
  4. Convert 1200 mL to litres.
  5. If a bucket holds 10 L, how many 250 mL cups fill it?
Answers (click to show)
1) 3 L = 3000 mL.
2) 1.5 L = 1500 mL. 1500 ÷ 250 = 6 bottles.
3) 4 L = 4000 mL. 4000 ÷ 500 = 8 cups.
4) 1200 mL = 1.2 L.
5) 10 L = 10,000 mL. 10,000 ÷ 250 = 40 cups.

Tips for learners

  • Remember: 1 L = 1000 mL. This helps converting quickly.
  • Use things at home to practise: bottles, cups, jerrycans.
  • When measuring, read the mark at eye level for accuracy.

Good practice: measure water into different containers and write their capacities. Try to use a measuring jug that has mL marks.


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