Understanding Intrinsic 'Fraction' Function in Fortran

[PaulDirac]

I have tried to use the intrinsic' fraction' function in Fortran but have failed to understand how it works. I thought that it would return the fractional part of a real number, but when I ran a few numbers through it, I got something that was a far cry from what I expected. For example, I tried fraction(10.0) and got 0.625. Can you tell me what's wrong?

 

[mfb]

10 = 0.625 * 2⁴

https://gcc.gnu.org/onlinedocs/gfortran/FRACTION.html