Suggestions:
Include the involved values in your posting so we can gauge how the
math comes out.
It's healthiest to always use parentheses in multi-function
computations, to avoid ambiguity and erroneous results.
When you go for decimal results, habitually employ decimal constants
(100.0), for both human emphasis and as hints to expression evaluators
which may react to integer values in a certain way.

   Richard Sims