AC9M1M01 • Year 1 Maths

Comparing Length, Mass, Capacity and Duration

Objects and events can be compared by length, mass, capacity or duration. The attribute must match the question.

Learning goals

Objects and events can be compared by length, mass, capacity or duration. The attribute must match the question.

Learning routine: Choose attribute → Compare fairly → Order → Explain

Success looks like

  • Choose attribute
  • Compare directly
  • Compare indirectly
  • Order objects/events
  • Communicate reasoning
Concept model and worked application

Choose the measurement attribute first

length = longer/shortermass = heavier/lightercapacity = holds moreduration = takes longer

Use the correct comparison words for the attribute.

Compare directly when possible, indirectly when needed

side by sidebalance scalesame cupsame timer

A fair comparison uses the same start, tool or unit.

Explain your thinking: Say what each part of the model represents, then explain why the answer or conclusion follows.

Compare the same attribute fairly

Compare and order objects using a named attribute and evidence.

Worked example

Two shelves cannot be moved together. How could you find which is longer?

  1. Use a strip of paper to mark the length of the first shelf, starting at one end.
  2. Place that same strip along the second shelf, lining up the starting ends.
  3. Compare the far ends. The shelf reaching farther is longer. The strip transfers a length between objects.

Watch for this mistake: An object can be taller yet hold less, or larger yet lighter. Decide whether you are comparing length, mass, capacity or duration.

Try it, then explain

  1. A balance tilts down on the side with the stone. Which is heavier: the stone or the pine cone on the other side?

    Hint

    The heavier side moves down.

    Answer and explanation

    The stone is heavier.

  2. Cup A fills 3 identical small scoops; cup B fills 5. Which has greater capacity?

    Hint

    Compare how much each holds using the same scoop.

    Answer and explanation

    Cup B. It holds more of the same-sized scoops.

Australian Curriculum elaborations

These curriculum examples extend the central model into varied contexts. They are learning contexts, not extra definitions to memorise.

E1

using a piece of string to indirectly compare the length of several objects, deciding which will fit within a space; using comparative language to describe the order: shortest, short, longer, longest

Try and explain: A string exactly matches a shelf's length. A box is longer than that string. Will the box fit along the shelf without overhanging?

Answer and teaching point

No. The string transfers the shelf's length, and the box exceeds it. Align the same starting ends when comparing.

E2

ordering the mass of 3 or more objects such as rocks, using hefting and balance scales; using comparative language to explain the order: lightest, light, heavier, heaviest, and how they decided on the order

Try and explain: Balance scales show A heavier than B and B heavier than C. Order them from lightest to heaviest.

Answer and teaching point

C, B, A. Use the mass comparisons; the biggest-looking object is not necessarily the heaviest.

E3

pouring sand/rice/water from one container to another to compare and order the capacity of 3 or more containers; describing the order of the results in terms of which holds the most/least, and those in between

Try and explain: Three containers hold exactly two, five and three identical cups of water. Order their capacities.

Answer and teaching point

Two cups, three cups, five cups: least to greatest. Using the same cup makes the comparisons meaningful.

E4

creating sand timers from everyday items or recycled material and comparing them to order the duration of time required for the sand to run through

Try and explain: Three sand timers start together. Red empties first, blue next and green last. Which measures the longest duration?

Answer and teaching point

Green. Starting together allows the finishing times to show which duration is longest.

E5

investigating situations where First Nations Australians estimate, compare and communicate measurements; for example, the duration of seasons; understanding animal behaviour using the length of animal tracks; investigating capacity through water management techniques of First Nations Australians, such as traditional water carrying vessels and rock holes

Cultural safety: Use a community-approved source, name the specific Nation or community where the source does, and avoid presenting diverse First Nations knowledges as one generic tradition. Follow local cultural and intellectual property protocols before inviting community participation.

Common misconceptions and traps
  • Wrong attribute — Check whether the question asks length, mass, capacity or duration.
  • Unfair comparison — Line up ends or use the same container/tool.
  • Only saying bigger — Use precise words such as longer, heavier, holds more or takes longer.
Guided learning activities

Attribute sort

Sort classroom questions by length, mass, capacity or duration.

Model: Which is heavier? → mass

Order objects

Order three pencils from shortest to longest.

Model: short → medium → long

Explain fairly

Tell why your comparison is fair.

Model: same starting line

Revision Notes

Key idea: Objects and events can be compared by length, mass, capacity or duration. The attribute must match the question.

Remember

  • Choose attribute
  • Compare directly
  • Compare indirectly
  • Order objects/events
  • Communicate reasoning

Quick questions

  • Which attribute uses heavier/lighter?
  • How do you compare two lengths fairly?
  • What does capacity mean?
  • Order three events by duration.

Return to the concept model if an answer is uncertain. Use the model to explain, not just to guess.

Official curriculum reference

AC9M1M01: compare directly and indirectly and order objects and events using attributes of length, mass, capacity and duration, communicating reasoning

Australian Curriculum Version 9.0

Practice, test and teacher resources

Use the Practice Sheet for written or hands-on work, Practice for supported feedback, and Test when the student is ready to demonstrate independent mastery.

🎥 Optional Video Lesson

The SkillrHub lesson remains the primary learning resource. This optional video reinforces the explanation; you can complete the lesson and practice without watching.

Back to the lesson

Before you watch:

  • Pause after each worked example.
  • Try the examples yourself.
  • Return to the SkillrHub lesson before continuing.
Recommended: Measuring

Scratch Garden — Compare lengths and heights as one part of comparing measurable attributes.

As you watch: How can you make a comparison fair when the objects start in different places?

Load video player Loads YouTube in this lesson. See the video notice below.

Try it: Line up three pencils at one end. Order them from shortest to longest and explain your choice.

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Curriculum equivalents: Victoria, NSW and international

Curriculum equivalents for Comparing length, mass, capacity and duration

Mapped skill: compare directly and indirectly and order objects and events using attributes of length, mass, capacity and duration, communicating reasoning

These references identify matching or closely related learning. Curriculum sequence, terminology and depth vary, so teachers should use the mapped skill and lesson difficulty to confirm suitability.

RegionCurriculum frameworkClosest level or code
AustraliaAustralian Curriculum v9.0AC9M1M01 · Year 1
VictoriaVictorian Curriculum F–10 Version 2.0 — MathematicsVC2M1M01 · Level 1
New South WalesNSW Mathematics K–10 Syllabus (2022)MA1-GM-02 + MA1-3DS-02 + MA1-NSM-01 + MA1-NSM-02 · Stage 1
United States (USA)Common Core State Standards for MathematicsGrade 1
Canada (Ontario)Ontario Curriculum — MathematicsGrade 1
United Kingdom (England)National Curriculum in England — MathematicsYear 2, Key Stage 1
IndiaNCERT / CBSE — MathematicsClass 1

Australian Curriculum v9.0 is the canonical source for this SkillrHub lesson. Victoria and NSW entries name the closest published state codes or outcomes; international entries are planning references rather than claims of identical curricula.

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