Math // Measurement
Choosing measurement units
Choose and use appropriate standard units to measure length (m/cm), mass (kg/g), temperature (°C), and capacity (litres/ml) to the nearest appropriate unit
Quick check
If you ask the learner whether to measure a swimming pool or a piece of paper in cm or m, can they pick the sensible unit for each — and explain why?
Ask this to see whether the topic is secure.
Topic // Mastery
What mastery looks like
- Measure the length of a table in centimetres using a ruler
- Weigh an object in grams using a scale
- Measure the capacity of a container in millilitres using a measuring jug
Topic // Map
Where this fits
- RequiredMust come first
- HelpfulHelps, but not essential
Before this
3 topicsMeasurement // Ages 5 to 6
Using standard units for length extends from beginning to measure length
- Capacity and volumeRequired
Measurement // Ages 5 to 6
Using standard units for capacity extends from beginning to measure capacity
- Measuring mass and weightRequired
Measurement // Ages 5 to 6
Using standard units for mass extends from beginning to measure mass
You are here
Choosing measurement units
Ages 6 to 7 // Method
Leads to
3 topicsMeasurement // Ages 6 to 7
Comparing and ordering measurements with symbols requires being able to measure in standard units
- Calculating with measurementsRequired
Measurement // Ages 7 to 8
Extends Y2 standard unit measurement to include mm and to add/subtract measures
- Measuring length (age 7+)Helpful
Measurement // Ages 7 to 8
Choosing appropriate tools builds on choosing appropriate units
Topic // Research-informed
Teaching notes
From the Marble Skill Taxonomy. These notes have not been validated in classrooms, so treat them as a starting point for your own judgement.
The approach
Children aged 6–7 learn to measure in appropriate standard units: length (m/cm), mass (kg/g), temperature (°C) and capacity (litres/ml). The skill has two joined parts: first name the attribute (how long? how heavy? how much fills it? how hot?) so the unit family and instrument match, then choose the grain of unit that yields a readable, precise number (a pencil in cm, not m; a drink in ml, not litres), and read the instrument to the nearest sensible mark.
Common misconceptions
- Uses a unit or tool from the wrong attribute — e.g. reaches for a ruler to find 'how much water', or gives grams for a length.
- Picks the wrong grain — measures a pencil in metres ('0 m') or a room laboriously in centimetres — not choosing to the nearest appropriate unit.
- Happily reports a non-standard count ('6 cubes') when a standard measurement is asked for, not seeing why standard units matter.
- Reads the instrument carelessly — doesn't measure to the nearest mark, mis-reads the jug's meniscus or the scale.
Useful representations
- A measuring station: ruler/tape, kitchen scale, measuring jug, thermometer, with unit dials m/cm, kg/g, l/ml, °C
- Benchmark objects for each unit (a metre stick, a 1 kg bag, a 1 litre bottle)
- A sorting chart matching everyday objects to their sensible unit
- The 'same object, different hand-spans' contrast motivating standard units
Teaching practices
- Name the attribute before choosing a unit — length, mass, temperature or capacity — so the unit family and the instrument match what is being measured.
- Teach grain choice explicitly: which unit gives a sensible, readable number for THIS object (cm for a pencil, m for a room), using benchmark sizes to judge.
- Establish why standard units at all — contrast two children's hand-spans giving different counts — so children see standard units let everyone compare.
- Give a mixed 'measuring station' across all four attributes so choosing (not just reading) is the practised act.
- Introduce standard units once the need is understood; the progression warns that heavy early use of many varied non-standard units can actually interfere with grasping why standard units are needed.
Activities to try
- 1
Measuring station: choose the tool and the unit
Why it works: You first decide what kind of quantity you are measuring so the unit family and tool fit, then choose a unit grain that gives a sensible, readable number.
- Set out a mixed set of objects one at a time — a pencil, a table, an apple, a jug of juice, a cup of water (and, if available, something whose temperature matters) — with a ruler/tape, a kitchen scale, a measuring jug and a thermometer all available.
- For each object, first say out loud what KIND of measurement this is: how long? how heavy? how much fills it? how hot?
- Pick the matching instrument, then choose the standard unit (m or cm, kg or g, litres or ml, °C).
- Measure to the nearest mark and state the amount with its unit.
- Try a deliberate mismatch — measure the pencil in metres — and notice the number is useless (to the nearest metre a pencil rounds to '0 m'); then switch to centimetres and get a clean reading (a real pencil is usually somewhere between about 10 cm and 19 cm, depending on how much it has been sharpened).
- 2
Why standard units at all — the hand-span contrast
Why it works: Standard units let everyone agree and compare, because a non-standard unit changes from person to person.
- Measure the same object (e.g. a table) in hand-spans with two different people and record both counts — for example one person gets 8, another gets 9.
- Discuss why the two counts differ for the same table.
- Re-measure with a ruler in centimetres and compare: everyone gets the same number.
- Explain in your own words why we use standard units like centimetres instead of hand-spans or cubes.
- 3
Sort objects to their sensible unit
Why it works: Each attribute and each sensible size has a matching unit family and grain, which a benchmark size helps you judge.
- Sort a set of everyday objects under the unit you would use: m, cm, kg, g, litres, ml, °C.
- Answer targeted questions such as 'Which unit would you use to weigh an apple?' and justify the choice, rejecting a too-big option like kilograms in favour of grams.
- Pair each unit with a benchmark object (a metre stick, a 1 kg bag, a 1 litre bottle) and use the benchmark to sanity-check your sorting.
Topic // Standards
Curriculum standards
- The national curriculum in England: Key stages 1 and 2 framework document
- Maths/Y2/M/1
Math // Measurement
More in Measurement
- Measuring length (age 6+)Ages 6 to 7MethodMeasure the length of an object using same-size length units laid end to end with no gaps or overlaps
- Measuring lengthAges 6 to 7MethodOrder three objects by length and compare the lengths of two objects indirectly using a third object
- Number of minutes in an hourAges 6 to 7ConceptKnow the number of minutes in an hour and the number of hours in a day
- Telling Time: MinutesAges 6 to 7RepresentationTell and write the time to five minutes, including quarter past and quarter to, and draw clock hands to show these times
- Sequence intervals of timeAges 6 to 7MethodCompare and sequence intervals of time
- Money Addition & SubtractionAges 6 to 7MethodSolve simple money problems involving addition and subtraction, including giving change
- Adding money and giving changeAges 6 to 7MethodFind different combinations of coins that equal the same amount of money
- Pounds & Pence NotationAges 6 to 7LanguageRecognise and use symbols for pounds (£) and pence (p) and combine amounts to make a particular value