PROBLEMS RELATED TO APPLYING OPERATIONS :  Some of us were testing Class 4 children with addition and subtraction problems. We gave them sums that were written horizontally and those that were written vertically. Some of the addition sums involved carry-over, and some of the subtraction sums involved borrowing.

When we looked at the answer sheets of the children, we had strange observations. About the children who had produced correct answers for all the questions, we couldn't learn much. About those who, had done everything or nearly everything wrong, we could only conclude that they needed to re-learn addition and subtraction using concrete materials. From the answer sheets of those who had made mistakes in some of the questions, we could learn quite a lot.