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Unit: Shape, Space and Measures

Measurement and Scales

Measurement questions use real instruments, marked scales, temperature, units, simple conversions and scale drawings in practical situations.

Supports assessment standards: 2.1, 2.3, 2.4

Topic explanation

Always check the unit before calculating. A correct number with the wrong unit can still be wrong.

For common conversions, use the fact you know: 100 cm = 1 m, 1000 g = 1 kg, and 1000 ml = 1 litre.

Read rulers, weighing scales, measuring jugs and thermometers to the nearest marked division. Check the unit before recording the value.

Scale drawings use a fixed relationship. If 1 cm stands for 4 m, then 2 cm stands for 8 m. A basic scale factor multiplies every matching length by the same number.

Practical instrument examples

These are solved teaching examples with different values from generated practice.

Quick methods

Length
100 cm = 1 m and 1000 m = 1 km
Mass
1000 g = 1 kg
Capacity
1000 ml = 1 litre
Read a scale
Work out one interval, then match the marker to a division.

Worked examples

Example 1

Change 3 m into centimetres.

  1. There are 100 cm in 1 m.
  2. Centimetres are smaller than metres, so multiply by 100.
  3. 3 × 100 = 300

So: 3 m = 300 cm

Example 2

A rectangle is 8 cm long and 5 cm wide. What is its perimeter?

  1. Perimeter means the distance around the outside.
  2. Add all four sides: 8 + 5 + 8 + 5.
  3. 8 + 5 + 8 + 5 = 26

So: The perimeter is 26 cm.

Example 3

On a scale drawing, 1 cm represents 4 m. A path is 3 cm on the drawing. What is the real length?

  1. Each 1 cm on the drawing stands for 4 m in real life.
  2. Multiply the drawing length by 4.
  3. 3 × 4 = 12

So: The real path length is 12 m.

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