Year 2 Mathematics · AC9M2M01

Measure and compare length, capacity and mass

Choose a suitable informal unit, use equal units fairly, and explain why smaller units can give a more accurate measure

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Key conceptTeach from the board
  1. Length: A pencil measures 7 identical paperclips. Another measures 9 of the same paperclips. The second pencil is longer by 2 paperclips.
  2. Capacity: Container A holds 6 equal cups; B holds 9 equal cups. B holds 3 cups more.
  3. Mass: A toy balances with 8 equal blocks and a book with 11. The book has greater mass by 3 block-units.
  4. Unit choice: Measuring the classroom width with tiny counters would work but be inefficient; larger equal footsteps or tiles are more suitable. Measuring a pencil with footsteps would be too coarse.
Clean visual examplesOne-page board

Clean one-page examples

AC9M2M01 - Measure and compare length, capacity and mass
Example 1

Length: A pencil measures 7 identical paperclips. Another measures 9 of the same paperclips. The second pencil is longer by 2 paperclips.

Example 2

Capacity: Container A holds 6 equal cups; B holds 9 equal cups. B holds 3 cups more.

Example 3

Mass: A toy balances with 8 equal blocks and a book with 11. The book has greater mass by 3 block-units.

Example 4

Unit choice: Measuring the classroom width with tiny counters would work but be inefficient; larger equal footsteps or tiles are more suitable. Measuring a pencil with footsteps would be too coarse.

Curriculum examplesCurriculum examples
  • E1: choose suitable informal units for length, including larger units for long objects and smaller units for greater accuracy.
  • E2: compare container capacity using the same unit, record results and explain the measurement process.
  • E3: compare mass with balance scales and equal informal mass units.
  • E4: recognise why the same informal unit is required and how unit size affects the count.
  • E5: investigate specific First Nations uses of body-based uniform informal measurement in context.
  • E6: investigate measurable attributes of animal tracks interpreted in specific First Nations contexts.
Questions and answersWith answers
  • Choose the attribute first: length, capacity or mass.
  • Use one uniform informal unit throughout a comparison.
  • No gaps or overlaps for length.
  • Use the same cup/scoop for capacity.
  • Use equal-mass units on a balance scale.
  • Smaller units can give a more accurate measure but usually create a larger count.

Mastery check: Explain why measuring the same table with adult shoe lengths and child shoe lengths can give different numbers even though the table has not changed.

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