ABSTRACT
In using written numbers the pupil has to learn that a '2' can either represent the quantity 'two' or it can represent 'twenty', 'two hundred', 'two thousand' etc, depending on where it is positioned. There are no dues to tell you what you are looking at except the position of the 2 relative to the other numbers. The number 12 is different from 21 only because of the order in which the numbers are written.
