This is where you can use beads on a large string to show 200.
Or have 20 beads only for 0-20.
Ask the kids to show a certain number and then you 'bust it'
So 20 can be 12 and 8, 13 and 7, 19 and 1, 10 and 10
Have beads in groups of 10 in different colors.
Once the kids have got small numbers under control they can do use much bigger numbers.