ALGORITHM FOR DIVISION : If you ask a 10 or 1 1-year-old child to solve, say, 81 + 9, the chances are that she will correctly do it. But if you ask her to solve, say 72 + 3, there is a strong possibility that she will get it wrong. This is because; in this case she has to resort to an algorithm which she has blindly followed, without understanding what is going on or why it works.
When we met some children of Class 5 in a nearby primary school and gave them division problems to do, many of them came up with errors like Why did we get such solutions? This is because the children have not understood how and why the algorithm works. In fact, most adults don't understand this either. For instance, how many of us know why we move from left to right while dividing, and move from right to left while applying the other operations?, Let us consider this 'peculiarity'.