Weight and Capacity

Compare how heavy things are and how much containers hold.

  • Define and explain Weight and Capacity in your own words
  • Use key terms such as Capacity accurately
  • Apply what you have learned to new examples and questions
  • Avoid the common mistakes learners make with this topic

This lesson focuses on Weight and Capacity: compare how heavy things are and how much containers hold.

Definition: Weight and Capacity

Compare how heavy things are and how much containers hold.

Key ideas

Comparing measures

Words like longer, heavier and holds more only make sense when you compare two things directly — always name both sides of the comparison.

Measuring length

Longer things cover more distance, and we measure length with centimetres and metres using a ruler. Always line up the 0 mark with one end.

Key term — Capacity: How much a container can hold, measured in millilitres or litres.

Sorting the toy box

A toy box holds 12 triangles, 8 squares and 5 circles. How many more triangles than squares are there, and what is the total of all three shapes?

More triangles than squares: 12 − 8 = 4. Total shapes: 12 + 8 + 5 = 25.

Answer: 4 more triangles; 25 shapes altogether.

Common mistakes
  • Calling every four-sided shape a square A square needs four equal sides and four right angles; a rectangle has opposite sides equal instead.
  • Reading the wrong end of the ruler Always start measuring from the 0 mark, not from the end of the ruler.

Practice

A jug holds 500 ml. You pour in 250 ml. How much more can it hold?
Subtract what is already in the jug.

250 ml — 500 − 250 = 250.

Order these by weight, lightest first: an apple, a bag of flour, a grape.
Picture holding each one.

Grape, apple, bag of flour — from lightest to heaviest.

How many sides does a hexagon have?
Think of the prefix hex-.

6 — a hexagon has six sides and six vertices.

Which is longer: 1 metre or 90 centimetres?
How many centimetres are in a metre?

1 metre — it equals 100 cm, which is more than 90 cm.

Quick check

Weight and Capacity — quick check

Which of these best defines "Capacity"?

How much a container can hold, measured in millilitres or litres.

A ribbon is 45 cm long. 15 cm is cut off. How long is left?

30 cm — 45 − 15 = 30.
Key takeaways
  • Weight and Capacity: compare how heavy things are and how much containers hold.
  • Comparing measures: Words like longer, heavier and holds more only make sense when you compare two things directly — always name both sides of the comparison.
  • Side: A straight edge of a flat shape.
  • Watch out for: calling every four-sided shape a square