Measuring: maths lessons by year

What's taught, year by year

The steps in measuring, in the order children usually meet them. Years are named as in Australia; the ages are a guide.

Big and small, long and short: talk about size. Use everyday words to say which of two things is bigger, longer, taller or heavier.

Compare two lengths: longer, shorter, taller. Line up two objects from the same start point and say which is longer or shorter.
Compare mass: heavier and lighter. Feel and use a balance to tell which of two objects is heavier or lighter.
Compare capacity: full, empty, holds more. Pour between containers to find which holds more or less and use full, half full and empty.

Order three or more objects by length. Put several objects in order from shortest to longest and explain how you know.
Compare lengths using a third object. Use a string or strip to compare two lengths that cannot be placed side by side.
Measure length with informal units end to end. Measure an object with same-sized units such as paper clips laid end to end with no gaps.
Measure mass and capacity with informal units. Count how many cubes balance an object or how many cups fill a container.

Why we use the same units: standard units. Explain why units must all be the same size and why a bigger unit gives a smaller count.
Measure length in centimetres with a ruler. Line up a ruler at zero and read the length of an object to the nearest centimetre.
Measure longer lengths in metres. Use a metre stick or tape to measure and compare lengths in metres.
Measure in inches and feet (US customary). Measure lengths in inches and feet and compare the result with the same length in centimetres.
Estimate lengths in centimetres and metres. Use known lengths, like a finger width or a door height, to estimate before measuring.
Compare lengths and find how much longer. Measure two objects and subtract to find the difference in length.
Solve length word problems. Add or subtract lengths in the same unit to solve everyday problems.
Show lengths and differences on a number line. Represent lengths as distances from zero on a number line to add and subtract them.
Measure mass in kilograms and grams. Read a kitchen or bathroom scale to find mass in grams and kilograms.
Measure capacity in litres and millilitres. Read a measuring jug to find how much liquid a container holds in litres or millilitres.
Read scales with numbered markings. Read the value shown on a ruler, scale or jug where every mark is labelled.
Measure temperature in degrees Celsius. Read a thermometer in °C and compare hot and cold temperatures.

Choose the right unit to measure. Decide whether mm, cm, m or km (or g/kg, mL/L) suits an everyday measurement.
Measure accurately in millimetres. Measure short lengths to the nearest millimetre and know 10 mm make 1 cm.
Measure to the nearest half and quarter inch. Read a ruler marked in halves and quarters of an inch.
Read scales where not every mark is numbered. Work out the value of unlabelled intervals on a scale before reading it.
Use mixed units: metres and centimetres. Write a measurement in two units, such as 1 m 23 cm or 2 kg 300 g.
Add and subtract lengths, masses and volumes. Add and subtract measurements in the same unit to solve practical problems.
Kilometres for long distances. Know that 1 km is 1000 m and use kilometres for long journeys.

Convert between metric units. Change between km and m, m and cm, kg and g, L and mL by multiplying or dividing.
Convert customary units: feet, inches, pounds, ounces. Use 12 in = 1 ft, 3 ft = 1 yd, 16 oz = 1 lb and cups to quarts to convert US units.
Measurement word problems with all four operations. Solve multi-step problems about distance, mass and liquid volume using all four operations.

Write measurements as decimals. Write lengths, masses and volumes as decimals, such as 1.25 m or 0.5 kg.
Approximate imperial and metric equivalents. Know rough links such as 1 inch ≈ 2.5 cm, 1 pint ≈ 0.5 L and 1 kg ≈ 2 lb.

Convert units using up to three decimal places. Convert between units where the answer is a decimal, such as 1250 g = 1.25 kg.
Convert between miles and kilometres. Use 5 miles ≈ 8 km to convert distances both ways.