Pupils must be able to count in multiples of 2, 5 and 10 by the end of year 1 so that they are ready to progress to multiplication involving groups of 2, 5 and 10 in year 2. As with counting in ones, within 100 (1NPV–1 ), this is a skill that will need to be practiced throughout year 1.
As with 1NPV–1, forwards and backwards counting practice should include:
- reciting just the number names (for example, “ten, twenty, thirty…”), without the support of visual representations.
- counting with the support of visual representations and gestural patterns, for example pupils can point to numerals on a number line or 100 square, or tap out the numbers on a Gattegno chart.
- starting the forwards counting sequence with numbers other than 2, 5 or 10.
The 100 square and Gattegno chart are provided in criterion 1NPV–1 in figures 1 and 3 respectively.
When pupils are confident with the counting sequences, they should learn to enumerate objects arranged in groups of 2, 5 or 10 by skip counting, so they begin to connect counting in multiples with finding the total quantity for repeated groups. Pupils should first identify how many objects are in each repeated group, and then skip count in this number. They should leave year 1 understanding that when objects are grouped equally, it is more efficient to skip count than to count in ones. Recognising that a group of 5, for example, can be treated as a single unit is called unitising, and is the basis of multiplicative reasoning.