Order of operations (Score 1)

One reason is that, unlike other languages, you have control over the order of operations in a formula. This is important when executing the operations in the wrong order will cause an overflow. For example if A, B, and C are very large, (A - B) * C would give an overflow if executed as A*C - B*C. Whereas (presumably) D = A - B, then D * C would not. Some languages will " optimize" these statements and thus cause overflow.