Year 4 Mathematics · AC9M4M01

Interpret unmarked and partial units when measuring and comparing attributes of length, mass, capacity, duration and temperature, using scaled and digital instruments and appropriate units

interpret unmarked and partial units when measuring and comparing attributes of length, mass, capacity, duration and temperature, using scaled and digital instruments and…

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Learning goalsSay it simply

A scale can be read even when not every mark is labelled. The difference between labelled values is divided by the number of equal intervals. Keep the appropriate unit with every measurement.

Learning intention: Read whole and partial units on scaled and digital instruments; measure and compare length, mass, capacity, duration and temperature.

Learning routine: Choose the attribute, instrument and unit → check zero or the starting label → count equal spaces → find one interval → read the position → record and compare.

  • Explain what one scale interval represents.
  • Read a whole unit, half unit or other marked part and use an appropriate unit.
  • Estimate minutes on an analog clock without minute marks and find a short duration.
  • Operate a timer and make and check a scaled instrument.
Clean visual examplesWorked models

Clean one-page examples

Read, explain and apply the models
Model 1

Mass: count spaces from a labelled starting point

Part of a mass scale200500gEqual spaces; only the end values are labelled.

Worked example: The labelled difference is 500 − 200 = 300 g. Six equal spaces share that difference, so each is 50 g. The pointer is three spaces after 200 g: 200 + 50 + 50 + 50 = 350 g.

Teacher asks: “Why did we divide by six, not seven?” Expected response: Seven marks enclose six spaces. If a learner counts marks, touch each space together and recount.

Model 2

Length: a reading is different from a length when the start is not zero

Measuring with a worn ruler012cmEqual spaces; only the end values are labelled.

Worked example: The strip begins at 2 cm and ends at 9 cm. Its length is 9 − 2 = 7 cm. The ruler’s edge is not automatically its zero mark.

Transfer: A scale from 500 to 600 mm with ten equal spaces has 10 mm intervals. The sixth space after 500 is 560 mm. A tape reading of 5.25 m is 5 m and one quarter of a metre.

Model 3

Capacity: whole litres and quarter litres

Measuring jug0 L2 LRead theliquid level.

Worked example: Eight equal spaces cover 2 L, so each is 0.25 L. Seven spaces give 1.75 L. On a 0–1 L scale with ten equal spaces, each space is 0.1 L = 100 mL; seven spaces give 0.7 L = 700 mL.

Comparison: 1.25 L is 1250 mL. It is 70 mL more than 1180 mL. Compare like units before deciding. For a real jug, place it on a level surface and look at the liquid level straight on.

Model 4

Temperature: interpret the partial degree

Thermometer28 °C30 °C

Worked example: Four equal spaces span 30 − 28 = 2 °C. Each is half a degree. The first space above 28 is 28.5 °C. A digital reading 24.5 °C means 24 and a half degrees Celsius.

Compare instruments: From 20 to 30 °C in five spaces, each space is 2 °C and the third space above 20 is 26 °C. On a kitchen scale from 0 to 2 kg in four spaces, each is 0.5 kg and the third space is 1.5 kg. The interval size belongs to that instrument.

Model 5

Clock: estimate unmarked minutes, then find a duration

Estimate to the nearest minute123456789101112

Worked example: The short hand is between 9 and 10. The minute hand is about two fifths of the way from 8 to 9. Those numbers stand for 40 and 45 minutes, so the time is about 9:42. From 9:42 to 9:50 is about 8 minutes.

Teacher says: “Imagine five equal minute spaces between neighbouring hour numbers.” Estimate to the nearest minute; do not call every position exactly a multiple of five.

Model 6

Digital duration and a real timer

Elapsed-time timer02:35Display format: minutes : seconds

Worked example: This display is labelled minutes : seconds. 02:35 means 2 minutes 35 seconds, not 235 seconds. For a 45-second activity set 00:45, start it, and observe the alert at zero. An activity starting at 10:20 for 15 minutes needs a finishing alarm at 10:35.

Check: A countdown starting at 03:00 and now showing 01:00 has run for 2 minutes; the display shows the remaining time.

Curriculum examplesTeach every elaboration

Content description: interpret unmarked and partial units when measuring and comparing attributes of length, mass, capacity, duration and temperature, using scaled and digital instruments and appropriate units

E1: reading the mass of objects measured with digital and analog kitchen scales and explaining what unit of mass the lines on the analog scales refer to

Teach and model: Read the analog scale above (350 g), saying that each line after zero or another label advances by 50 g. Compare a zeroed digital scale showing 1.25 kg with 1250 g: they are the same mass. Measure two objects with real kitchen scales and record readings with units. Evidence: an actual reading, correct unit and an explanation of the analog interval or digital display.

E2: deciding on which attribute, unit and measuring instrument to use to compare the length and mass of various things, such as the distance travelled by an object in a science investigation; explaining the use of units such as grams or millimetres to give accurate measures when needed

Teach and model: For a toy car’s travel distance use a tape measure and centimetres; for a paperclip’s mass use suitable scales and grams. Seedlings 34 mm and 38 mm tall differ by 4 mm, so millimetres make the small length difference clear. Student does: choose and use a real instrument to compare two objects; justify attribute, unit and instrument.

E3: using scaled instruments such as tape measures, measuring jugs, kitchen scales and thermometers, recording measures using whole units; for example, 560 millimetres, or whole and part units; for example, 5.25 metres, 1.75 litres, 2.5 kilograms, 28.5° Celsius

Teach and model: Rotate through ruler/tape, jug, scales and thermometer stations. Record examples such as 560 mm, 5.25 m, 1.75 L, 2.5 kg and 28.5 °C, explaining the whole and part units. Use actual classroom objects as well as diagrams. Look for: starting labels, equal-space counts, unit labels and honest approximate readings between marks.

E4: reading and interpreting the scale of an analog clock without marked minutes to estimate the time to the nearest minute and to determine the duration of time between events

Teach and model: Use the unmarked-minute clock model to estimate 9:42, then count about 8 minutes to 9:50. Ask a partner to explain the minute-hand position. Quick check: about two minutes before the next hour means the minute reading is about 58, with the short hand still before the next hour.

E5: using the timer or alarm function of a clock to alert when a specified duration has elapsed from a given starting time; for example, the different activities of an exercise routine

Teach and do: Set 00:30 on a minutes : seconds timer for a quiet activity, then 00:20 for a rest. Observe each alert and record a 50-second planned total. Also set a finishing alarm from a given starting time, such as 10:20 plus 15 minutes = 10:35. Evidence: actual operation and observed alert, not only selecting a setting.

E6: making a scaled measuring instrument such as a tape measure, ruler, sand timer, sun dial or measuring cup using scaled instruments and direct comparisons

Make and check: Copy an accurate ruler onto a paper strip: 0–10 cm, equal centimetre intervals and half-centimetre marks. Measure an object with the homemade and original rulers and compare the records. Alternatively, use a jug to add measured 100 mL portions to a clear container and mark 100, 200, 300 and 400 mL. A widening cup may have unequal height gaps for equal volumes. Evidence: the actual calibrated instrument, direct comparisons and a trial reading.

E7: exploring the different types of scaled instruments used by First Nations Ranger Groups and other groups to make decisions about caring for Country/Place, and modelling these in local contexts

Public context: JCU TropWATER’s seagrass project describes work with First Nations Land and Sea Rangers and Traditional Owners to deploy temperature loggers. Its named Ranger image credits include Wuthathi, Yuku Baja Muiliku, Gidarjil and Darumbal Rangers. Use this specific published account to discuss temperature instruments; do not present it as one practice of all First Nations communities.

Local classroom model: Compare two safe classroom temperatures with a thermometer and a two-minute observation timer. Invented example: 27.5 °C then 28.5 °C shows a rise of 1 °C. Label invented readings and classroom observations clearly. Discuss how a logger can repeatedly record the same attribute over time. A classroom temperature difference alone does not establish the condition of a real seagrass site.

Questions and answersWith worked answers

Important questions and answers

  1. What is one interval from 0 to 1 L in ten equal spaces?

    Answer: 0.1 L or 100 mL. There are ten spaces, not eleven.

  2. How is 350 g located on a 200–500 g scale with 50 g spaces?

    Answer: Three spaces after 200 g: 200 + 150 = 350 g.

  3. How do 1.25 L and 1180 mL compare?

    Answer: 1.25 L = 1250 mL, so it is 70 mL greater.

  4. What does 02:35 mean on a minutes : seconds timer?

    Answer: 2 minutes 35 seconds. The colon separates minutes and seconds.

  5. Why are marks and intervals different?

    Answer: An interval is a space between marks. Two end marks make one space; seven marks make six spaces.

Guided learning activitiesMeasure and make
  1. Mystery scale: label every 50 g interval from 200 to 500 g.

    Answer: 200, 250, 300, 350, 400, 450, 500 g. Seven marks make six equal intervals.

  2. Instrument stations: measure a pencil, a safe object’s mass, a cup’s capacity and a safe classroom temperature.

    Answer: Records vary. Require actual instrument use, zero/start check, the attribute, reading and unit. A ruler gives length; scales mass; a jug capacity; a thermometer temperature. Compare a digital reading with an analog reading where equipment permits.

  3. Compare after conversion: 1.25 L versus 1180 mL; 1.4 kg versus 1350 g.

    Answer: 1250 mL is 70 mL more; 1400 g is 50 g more. Rename quantities with the same unit before comparing.

  4. Calibration workshop: make, label, test and improve a paper ruler or measuring cup.

    Answer: Inspect the actual instrument and reference comparison. Accept any accurately calibrated construction; guessed markings alone do not show calibration.

Teacher action: Demonstrate one reading, ask a partner to explain another, then observe each learner measure. Pause check: If a learner counts marks, points at the ruler edge instead of zero, or omits the unit, model that step before continuing.

Practice and reviewCheck the method
  • Counting marks: count the spaces between labelled values.
  • Assuming every interval is one: calculate the labelled difference and share it over equal spaces.
  • Starting at the ruler’s edge: align with zero, or subtract a nonzero start.
  • Ignoring units or comparing unlike units: name the attribute and express both readings in the same unit.
  • Reading 02:35 as a decimal: check the display format; minutes and seconds use different units.
  • Equal-volume marks always equally high: directly measure portions when making a cup scale.

Materials and timing: Allow two or more lessons: one for scale-reading stations and one for calibration and timers. Use rulers, paper strips, kitchen scales, measuring jugs, clear cups, a safe thermometer, clocks and timers.

Prerequisites: count equal spaces, compare whole numbers, and recognise halves and quarters. Support: enlarge scales, start at zero, colour one interval and use whole/half units. Core: interpret unlabelled intervals and partial units across all five attributes and use real instruments. Extend: diagnose a nonzero start or compare two different scales for the same attribute.

Boundary: Teach accurate readings and meaningful comparisons. Formal measurement uncertainty, advanced instrument calibration theory and extensive later-year unit-conversion procedures are not required.

Assessment-style questions and review hints

  1. A thermometer spans 10 to 20 °C in five spaces. Its level is halfway between 16 and 18 °C. Read it.

    Review hint: Find one interval, then its halfway point. Answer: About 17 °C; half of a 2-degree space is 1 degree.

  2. A ruler reading starts at 3 cm and ends at 8.5 cm. Find the length.

    Review hint: Subtract the starting reading. Answer: 8.5 − 3 = 5.5 cm.

  3. Make and test a scaled paper ruler with half-centimetre marks.

    Review hint: Directly compare against an accurate instrument. Answer: Check an actual ruler with equal intervals, a known reference and a trial measurement recorded with units. Different valid trial lengths are accepted.

Exit ticketCheck the evidence
  1. A scale runs from 200 to 500 g in six spaces. Give one interval and the third reading after 200.

    Answer: 50 g per interval; 350 g.

  2. A clock’s minute hand is about three fifths of the way from 5 to 6, and its short hand is between 4 and 5. Estimate the time.

    Answer: About 4:28.

  3. Show your made instrument or an actual measurement record and explain how you checked it.

    Answer: Require a real instrument or actual measuring record, a correct unit and a direct reference/zero/interval check. Examples differ by object.

Mastery evidence: Correct interpretation across length, mass, capacity, duration and temperature, plus actual measuring and making. A completion tick alone does not demonstrate a practical skill. Revisit the relevant instrument station when a learner cannot explain its intervals.

Curriculum alignmentStart here

A scale can be read even when not every mark is labelled. The difference between labelled values is divided by the number of equal intervals, and measurements must include an appropriate unit.

Learning routine: Identify attribute/unit → Read labelled endpoints → Count equal intervals → Find interval value → Read partial position → Record and compare

Success looks like

  • Calculate interval values
  • Read partial units
  • Use scaled/digital instruments
  • Use related units to compare readings
  • Record and compare accurately
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