Grade 3 Mathematics Measurements – Capacity Notes
Mathematics — Measurements
Subtopic: Capacity (for age 8)
Capacity tells us how much a container can hold. We often measure capacity in litres (L) and millilitres (mL).
Important facts
- 1 litre (1 L) = 1000 millilitres (1000 mL).
- We use litres for big containers (jerrycans, water buckets) and millilitres for small ones (soda bottles).
- Common Kenyan examples: a jerrycan ≈ 20 L, a large water bottle 500 mL or 1 L.
Visual examples
1 L bottle
Half full 1 L = 500 mL
Used for water in many homes
Simple conversions
- 1 L = 1000 mL
- 2 L = 2000 mL
- 0.5 L = 500 mL
- 20 L jerrycan = 20 × 1000 mL = 20 000 mL
Worked examples
Example 1: How many millilitres are in 3 litres?
3 L = 3 × 1000 mL = 3000 mL.
Example 2: A water bottle has 750 mL. How many litres is this?
750 mL = 750 ÷ 1000 L = 0.75 L (three quarters of a litre).
Try these activities (do with real containers)
- Find three containers at home (e.g., mug, soda bottle, jerrycan). Write their labelled capacities.
- Estimate: Which holds more — two 500 mL bottles or one 1 L bottle? Write why.
- Pour water to show 250 mL using a 1 L bottle: mark where 250 mL, 500 mL and 750 mL are.
Practice questions
- Convert 4 L to mL.
- Convert 1500 mL to L.
- If Mama buys 2 jerrycans of 20 L each, how many litres does she have?
- A bottle holds 250 mL. How many such bottles make 1 L?
- Which is larger: 900 mL or 1 L? By how much?
Answers
- 4 L = 4000 mL.
- 1500 mL = 1.5 L.
- 2 × 20 L = 40 L.
- 1 L = 1000 mL, so 1000 ÷ 250 = 4 bottles.
- 1 L = 1000 mL, so 1 L is 100 mL more than 900 mL. 1 L is larger by 100 mL.
Tip for teachers and parents: Use real items (soda bottles, cooking jugs, jerrycans) so learners can see and feel capacity. Ask children to compare, pour and measure — this builds good understanding.
Note: These notes follow common primary lessons in Kenya for age 8 — keep language simple and use hands-on activities.