Place value
Add counters to each column and watch the number build. Ten in a column? Press Exchange to regroup. Expanded form underneath.
How to use it
- Press + and − under each column, or type a number and press Set. Random gives you one to read together.
- Put more than ten in a column (add 3 ones to 8 ones, say) and press Exchange to regroup ten of them as one in the next column. That is the whole of column addition in one picture.
- Untick Number to hide the total while the class works it out.