The IF function does not accept a value, how to fix it?

Question

excel

Dear experts, all the best!
Please tell me how to write the formula:
A1, B1, C1
(C1=any numerical value)
The task is this:
If A1=100%, then B1=0, otherwise B1=C1
Tried to use this formula: =IF(A1=" 100%";2-2;C1), but this option is not working due to the fact that the IF function does not take a digital value. With a literal value, everything works.

Thank you.

Answer 1

If the format is percentage and not text, then 100% is 1 .

Answer 2

=IF(A1=100%;2-2;C1)everything is working