If you get the chance go through a maths GCSE exam paper and count the number of questions that ask you to “give your answer correct to ……..”. If the question contains this request, then for each of the questions there will probably be a mark allocated for the answer being given to the required number of decimal places or significant figures. There could be as many as five or six marks on a particular GCSE maths paper. Suddenly approximating answers to the correct number of decimal places or significant figures becomes an extremely important part of the GCSE maths syllabus.
When doing your GCSE maths revision you must allocate time to practise rounding answers to a certain number of decimal places and also to a certain number of significant figures. Generally the two concepts are quite easy to master, but do take the time to practise because there are situations where the rounding can be tricky especially when there are zeros at the beginning or the end of the number.
The second piece of advice relates to the actual GCSE maths questions. When first reading through a question in the GCSE maths exam, check to see if the question requires the answer to be rounded to a specific number of decimal places or significant figures. If it does, highlight the fact straightaway. This should help you remember to do the rounding at the end of the question or it may alert you to check that the question has been rounded off correctly when you check through your answers at the end of the GCSE maths exam. You need to put this procedure into practice when doing any question during your GCSE maths revision. You would be amazed if you were told the number of marks that had been lost by candidates failing to round off answers correctly in GCSE maths exams. Ensure you don’t lose any marks for this particular error by adopting a strategy when you do your GCSE maths revision to alert you to this particular request in questions in the GCSE maths exams.