ABSTRACT
We all make mistakes, if only because we are human and imperfect. However, mistakes can be costly, annoying and embarrassing in real life and in examinations they will cost our marks. There are a number of checks that can usually be applied to test the correctness of our answers. Try to build an independent check into our calculations. A much better approach is to find a check that does not need reference to our original working. If we are presented with a problem with complicated numbers we can perform a quick check if we approximate all the input data and use that to get an approximate solution. When we are given equations to solve, one useful check is to put all our answers back into the original equations to see if the original relationships are true. If a dimensioned quantity is to be calculated we can check that the units of the answer match the requirement of the question.
