What each digit is worth
In 352 the 3 is worth three hundred, not three. Seeing that, and writing it, is the base of adding and subtracting with bigger numbers, regrouping included. These sheets go from counting blocks to writing numbers in expanded form, one small step at a time.
Three tasks
- Blocks. Count the flats, rods and cubes, then write the number.
- Tens and ones. 47 = 4 tens 7 ones; 352 = 3 hundreds 5 tens 2 ones.
- Expanded form. 352 = 300 + 50 + 2.
Next steps
Once place value is secure, move on to two-digit addition andsubtraction with regrouping.
Irish curriculum links
- InfantsStage 1: children develop a sense of ten as the foundation for place value and counting, for example with ten frames.
- 1st–2nd ClassStage 2: a digit’s value depends on its place. The continuum moves from two-digit numbers to at least 99, then three-digit numbers to at least 199.
- 3rd–4th ClassStage 3 explores equivalent ways of writing numbers in base ten, with whole numbers to 999 and beyond.
The NCCA toolkit gives a useful example: 46 is 4 tens and 6 units, but it is also 3 tens and 16 units. Asking children to show both with Dienes blocks is good preparation for exchanging in subtraction.
Expanded form, like 352 = 300 + 50 + 2, is one of several ways the curriculum expects children to represent a number, alongside blocks, drawings and words.
Summarised in our own words from the Primary Mathematics Curriculum (2023), the NCCA Mathematics Toolkit and ERC guidance on the Drumcondra Primary Mathematics Test.
