AC9M3M02: Measure and compare objects using familiar metric units of length, mass and capacity, and instruments with labelled markings

Accurate measurement requires a suitable instrument, correct starting point, careful reading of labelled markings and a unit in the answer.

Learning routine: Select instrument → Check zero and scale → Measure → Record unit → Compare

Success looks like

• Choose instruments
• Read rulers
• Read scales
• Record units
• Compare measurements

Success criteria:

• Choose instruments
• Read rulers
• Read scales
• Record units
• Compare measurements

Students should be able to compare everyday attributes, choose familiar informal or metric units where appropriate, and read simple measuring tools or time displays. Check that the unit and the quantity being measured are clearly distinguished.

Key idea: Accurate measurement requires a suitable instrument, correct starting point, careful reading of labelled markings and a unit in the answer.

Learning routine: Select instrument → Check zero and scale → Measure → Record unit → Compare

scale

the ordered markings on a measuring instrument

interval

the value between neighbouring scale marks

capacity

the amount a container can hold

What is the big idea in this topic?

Accurate measurement requires a suitable instrument, correct starting point, careful reading of labelled markings and a unit in the answer.

What routine should I use?

Select instrument → Check zero and scale → Measure → Record unit → Compare

How do I know I am ready to move on?

You can choose instruments, read rulers, read scales, record units, compare measurements and explain how your model or calculation supports the answer.

• Starting at ruler edge — Use the zero mark.
• Counting marks not intervals — Read the scale values.
• Missing unit — Every measurement needs its unit.

1. Where should an object begin on a ruler?

   • at the zero mark
   • at the ruler edge always
   • at 1 cm
   • at any mark without adjusting

2. Complete the measurement.

   Prompt: A line ending at the 13 cm mark is □ cm long.

3. Which is heavier?

   • 1 kg
   • 750 g
   • 500 g
   • 250 g

4. Explain how to work out the value of unlabelled intervals on a measuring jug.

5. Match the instrument to the attribute.

   Match: ruler • balance scale • measuring jug ↔ capacity • length • mass

6. Complete the comparison.

   Prompt: 1 200 mL is □ mL more than 800 mL.

1. Design a measurement station that compares length, mass and capacity with appropriate instruments.

2. Create a labelled scale with missing values and write instructions for another student to read it.

Explain the reasoning, not only the final answer.

1. Describe how to measure a broken pencil when the ruler's zero end is damaged.

2. A student counts 6 ruler marks and says the object is 6 cm long. Explain why intervals matter.

Review hint: Follow the routine “Select instrument → Check zero and scale → Measure → Record unit → Compare” and use the worked model to check whether your answer is reasonable.

• I can choose instruments.
• I can read rulers.
• I can read scales.
• I can record units.
• I can compare measurements.

Quick check: Read 13 cm on a ruler. • What is each interval from 0 to 1 L with 5 equal spaces? • Compare 750 g and 1 kg.

Read the topic guide and use the teacher slide for instruction. Students can then use the worksheet for written work, open Practice for supported feedback, or take the Test when they are ready.

The content description and elaborations below show the curriculum ideas taught in this unit. Items marked as teaching context support lesson planning.

• Content description: measure and compare objects using familiar metric units of length, mass and capacity, and instruments with labelled markings
• E1: making a measuring tape using metric units of length and using it to measure and compare things; for example, the girth of a tree; explaining that the lines on a ruler show the beginning and end of each unit
• E2: using a strip of centimetre grid paper to measure and compare the length of objects, connecting this with centimetre units on a ruler and using fractions of a graduation to give a more accurate measure
• E3: discussing how the capacity of a container or object usually refers to the amount of liquid it can hold, measured in millilitres and litres; comparing the capacity of different sizes of familiar drinks; for example, 600 millilitres, one litre, 2 litre and 3 litre milk containers
• E4: measuring and comparing the mass of objects and capacity of containers, using measuring jugs and kitchen or other scales and standard metric units of millilitres, litres, grams and kilograms; interpreting and explaining what the lines on the measuring jug or scales mean
• E5: comparing the capacity of different beakers used in science lessons and using the numbered graduations to measure out different capacities of liquid

Australian, Victorian and NSW alignment retained from the previous page

• Australian Curriculum Version 9.0 — ACARA
• Victorian Curriculum — VCAA
• NSW Curriculum — NESA

Official curriculum sites are the source of record.

• AC9M3M01 — Choosing Metric Units and Estimating
• AC9M3M03 — Time Units and Duration
• All Year 3 Mathematics topics

Curriculum equivalents for Measure and compare objects using familiar metric units of length...

Mapped skill: measure and compare objects using familiar metric units of length, mass and capacity, and instruments with labelled markings

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.

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.