Trying to get the remainder of a decimal by using Formula on a field

Hello Everyone,

Here is my situation.

I have a field in a table (named QuestionPosition)(type Decimal) that contains values like this:

1  2   3  4  5.1  5.2  5.3 ...

I want to have another field in the same table that stores just the remainder (in the above case a 0 for integer values and the 1 of the 5.1, 2 of the 5.2 etc.

I created the field in the table (named QuestionSubPosition) and tried to set the formula for it to QuestionPosition % 1 but it does not accept the formula.

The part that i do not understand is that i can set the formula to QuestionPosition / 1 it works (but not the results i want).

Any ideas on how i can get the results i want

Corey