The most common mistake
Children often start measuring from the end of the ruler, or from 1. On the printed-ruler sheets every object starts exactly at zero; on the “use your own” sheets they have to line it up themselves.
Real size
Every sheet is drawn to scale, so the objects are as long on paper as their measurements say. That makes it easy to check an answer with a real ruler.
Irish curriculum links
- InfantsStage 1 Measuring: children become aware that length, weight, capacity and area can be measured and compared, starting with longer and shorter.
- 1st–2nd ClassStage 2: children compare, approximate and measure with suitable instruments, such as a ruler, and record the result with a unit.
- 3rd–4th ClassStage 3 adds estimating, metric units with more precision, and renaming measures, such as 150 cm as 1.5 m.
Irish schools measure in metric units, and the toolkit notes that the metric system is built on multiples of ten. Keep the setting on centimetres; the inch option is there for other countries.
The toolkit also stresses that the size of the unit changes how many you need, so measure the same pencil with cubes or paper clips before the ruler. That step from non-standard to standard units is one Irish infant and junior classes spend real time on.
Summarised in our own words from the Primary Mathematics Curriculum (2023) and the NCCA Mathematics Toolkit.
