AC9M1M02 • Year 1 Maths

Measuring length with informal units: Year 1 Maths topic guide

measure the length of shapes and objects using informal units, recognising that units need to be uniform and used end-to-end

What students learn in AC9M1M02

This unit helps students build a clear, usable understanding of Measuring length with informal units. The goal is not to memorise one answer pattern. Students should be able to explain the idea, recognise it in a new example and apply it in a short practice or worksheet task.

  • Start with the main idea: measure the length of shapes and objects using informal units, recognising that units need to be uniform and used end-to-end.
  • Use concrete examples, pictures, oral explanation and short written responses before moving to independent practice.
  • using 2 different units; for example, pop sticks and pencils, to measure the length of an object such as a desk, and explaining why the number of units used may be different comparing the length of 2 objects such as a desk and a bookshelf by laying multiple copies of a unit and counting to say which is longer and how much longer; explaining why they shouldn’t have gaps or overlaps between the units as this will change the length of the unit
  • Finish with mixed questions so students must choose the correct strategy rather than copy the last example.

Curriculum coverage and elaborations

The content description and elaborations below show the curriculum ideas taught in this unit. Items marked as teaching context support lesson planning but may not appear in the initial eight-question activity.

  • Content description: measure the length of shapes and objects using informal units, recognising that units need to be uniform and used end-to-end
  • E1: using 2 different units; for example, pop sticks and pencils, to measure the length of an object such as a desk, and explaining why the number of units used may be different
  • E2: comparing the length of 2 objects such as a desk and a bookshelf by laying multiple copies of a unit and counting to say which is longer and how much longer; explaining why they shouldn’t have gaps or overlaps between the units as this will change the length of the unit
  • E3: measuring the distance between 2 locations using footsteps, comparing the results and explaining why there may be different results; for example, referring to the different length of footsteps as using different units
  • E4: measuring and comparing the length of objects using blocks; for example, comparing the height of 2 toys by stacking blocks one on top of the other and counting how many it takes to reach the height of each object to decide which is taller

How to use this unit

Read the topic guide, use the teacher slide for instruction, then complete the Worksheet, Practice and Test. These three activities use the same eight-question unit bank.

Teacher resource

AC9M1M02 teacher slide

Use this one-page PDF to introduce the key idea, vocabulary and teaching sequence before students begin the activities.

Open teacher slide (PDF)

Common mistakes to watch for

  • Rushing to a rule before checking the concrete model, drawing or number sentence.
  • Using the correct answer once but not being able to explain why it works.
  • Mixing up similar vocabulary such as more/less, before/after, longer/shorter or equal groups/sharing.

International curriculum mapping

This table gives closest-topic mapping for search and planning. The Australian Curriculum code is exact; overseas entries are broad equivalents because each jurisdiction structures outcomes differently.

RegionCurriculumClosest mapping
AustraliaAustralian Curriculum v9.0AC9M1M02 — measure the length of shapes and objects using informal units, recognising that units need to be uniform and used end-to-end
VictoriaVictorian Curriculum F-10Year 1 Maths: closest match in Measurement. Use this page as a VIC-aligned practice and worksheet reference.
NSWNSW CurriculumStage 1 Maths: closest content focus for Measuring length with informal units and related outcomes.
United StatesCommon Core / NGSSGrade 1 Common Core Mathematics/ELA closest topic match for Measuring length with informal units.
England / UKNational CurriculumKey Stage 1 / Year 1: closest programme-of-study match for Measuring length with informal units.
CanadaProvincial and territory curriculaGrade 1 closest topic match. Canada varies by province, so use this as a broad Ontario/BC-style learning outcome reference.
New ZealandNew Zealand CurriculumLevel 1 Maths: closest achievement-objective topic for Measuring length with informal units.
IndiaNCERT / CBSEClass 1 closest NCERT/CBSE topic match for Measuring length with informal units.

Related Year 1 Maths topics

Official curriculum references