int waitVal;
...
return 100 * (waitVal / 100);
This is NOT identical to "multiplying by 1."
The variable is an integer. It cannot store fractional parts. The math done on an integer variable is done only with integers, and so any fraction is immediately discarded.
Example: if waitVal were 356, then waitval / 100 would result in 3, not 3.56. Then 3 * 100 is 300.
The formula above just helped you round DOWN to the nearest 100.