INTRODUCTION : We are often confronted with children not being able to deal with H T 0, i.e. 'hundreds', 'tens' and 'ones' (or 'units'), with comfort, though they are supposed to have "learnt" the concept. For instance, take this friend of mine who has a fair amount of experience of interacting with students of Classes 6,7 and 8 in various schools in rural and semi-urban areas. On many occasions this interaction revolved around 'hundreds', 'tens' and 'ones'. He discovered that the children of these classes were not able to read 5-digit numerals though they were supposed to "know" such numbers. For example, the 2 in 20013 variously denoted 2 hundreds, 2 thousands, 2 lakhs and even 2 crores. It was quite obvious that they did not have a clue about the value that the position of the digits indicated. Of course, once a hint was given, many of items were able to quickly formulate the right answer.
This lack of understanding also shows up in problems of addition and subtraction. In addition sums all they know is that they must add column wise. Why? Because "Teacher says so". And when there are given problems involving addition of 3 or 4 numerals written one below the other, with each having 3 or 4 digits, they often write the digits of the answer in the wrong columns. This leads to what we think are unusual and unlikely answers ; of course, they don't think SO !
All this often frustrates the adults, who give up and end by labelling and/or scolding the children. Instead, shouldn't we ask ourselves whether we have really tried to see why the children don't understand? Could it be that they haven't been given enough activities to be able to clarify the concepts concerned in their minds? Or, could it even be that we, who are attempting to get the child to learn, are not clear about the concepts ?
We have looked into these problems in this unit, and have some suggestions to make. We hope that this unit will make you appreciate the depth of the problems, and that there is no single solution.
We also hope that studying this unit will generate confidence and interest in you to try out new methods of teaching the concept of place value in the decimal system.