Measuring Length

Compare and measure length using rulers and centimetres.

  • Define and explain Measuring Length 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 Measuring Length: compare and measure length using rulers and centimetres.

Definition: Measuring Length

Compare and measure length using rulers and centimetres.

Key ideas

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.

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.

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

Worked example: Measuring Length

Which is longer: 1 metre or 90 centimetres?

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

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

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

Practice

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

6 — a hexagon has six sides and six vertices.

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.

Name the solid with 6 square faces.
Picture a dice.

A cube.

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.

Quick check

Measuring Length — 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
  • Measuring Length: compare and measure length using rulers and centimetres.
  • Measuring length: Longer things cover more distance, and we measure length with centimetres and metres using a ruler.
  • Side: A straight edge of a flat shape.
  • Watch out for: reading the wrong end of the ruler