Because, We don't know whether how many decimals we get after that calculation. I know 1 is wrong in your case. Try some thing like below
I assume, this will return 1 because as i mentioned before line we are not understand the decimal point
I assume, The calculation part is wrong it should return 0, Because now ceil() function can understand the decimal points where we are using calculation of %. If this condition returns 0 then the condition true
If you want, More information he will offer you better than me marcus_sommer
Meantime, go to help and check Round() and Ceil() functions to understand.
Before develop something, think If placed (The Right information | To the right people | At the Right time | In the Right place | With the Right context)
In your case, you could try to multiply both sides of the equation with 100 and maybe add round to the left side (assuming that the numbers are not fixed, but part of e.g. an aggregation and right side is a constant threshold) to overcome this issue: