Refactor Manual Float Cast to just (float)

Previous algorithm appears to have intended to perform some type of
rounding. It actually just strips 0's. The `round()` method ends up
rounding to the number of digits before the trailing 0's which is always
the same and doesn't actually round anything.

- Change to `(float)` as it does the same thing with less code and is
  easier to read
Merge pull request #1592 from mkly/refactor_manual_float_casting

Refactor Manual Float Cast to just (float)