Marnitzg: My HP calculator will do Hex, octal, and binary arithmetic on integers only. I think there are special calculators which do general purpose radix arithmetic, but I do not know of any regular calulator which will do radix arithmetic on fractional values.
However, such values exist in the Mindscape of Mathematics.

Depending on the country you favor, a dot or a comma separates the integer and fractional parts of Hex (or other radix) numbers. In Hex: 3.2FA represents 3 + 2/16 + 15/256 + 10/4096

If you kept track of the radix point yourself, you could use your calculator to do hex arithmetic on fractional values. On my calculator, division would be a problem because it gives an integer quotient and no remainder. Perhaps you could do division if you added some trailing zeros to the dividend.

If you wanted to multiply 3C.F by 2.F5, you could use integer multiplication of 3CF by 2F5, getting B431B. Since there are 3 digits (total) to the right of the radix point in the multiplier and multiplicand, there must be 3 digits right of the radix point in the product. B4.31B is the product.

In this day and age, I would how many people know how to do multiplication and division by hand methods, keeping correct track of the decimal point.