my formula for the column total is =round(sum(a4:a15),2) but the answer is
wrong. I am adding 6.30+1.71+1.24 and it gives me a total of 9.27 (should be
9.28). The numbers in column are from a formula not numbers I just inserted
and I think this may be my problem but I don't know how to solve it. The
numbers are a result of a formula to calculate the GST from a number in
another column.

Help please.