REPEAT REGIONS

As you've found, relations are pretty terrible for doing things like calculating the fractional equivalent of a decimal number, because they lack basic looping capabilities, You're therefore forced to a rather unweildy clump of nested IF-ENDIF statements. It works, but is really not a nice construct.

Anyway, I don't know what kind of relations examples you've found but here's a chunk from one of my generic bolt models that is trying to calculate the "multiple of 2" fraction (2, 4, 8, 16, 32) that a given decimal number is closest to. Hopefully that's the kind of fraction you are after, and not things like 11/13 and the like

In this snippet, diaNom is the number being looked at, and txtDiaNom is the resultant string containing the fraction.

 txtDiaNom = ITOS ( floor ( diaNom * 32 ) ) + "/32"
 IF MOD ( floor ( diaNom * 32 ), 2 ) < 1
 txtDiaNom = ITOS ( floor ( diaNom * 16 ) ) + "/16"
 IF MOD ( floor ( diaNom * 16 ), 2 ) < 1
 txtDiaNom = ITOS ( floor ( diaNom * 8 ) ) + "/8"
 IF MOD ( floor ( diaNom * 8 ), 2 ) < 1
 txtDiaNom = ITOS ( floor ( diaNom * 4 ) ) + "/4"
 IF MOD ( floor ( diaNom * 4 ), 2 ) < 1
 txtDiaNom = ITOS ( floor ( diaNom * 2 ) ) + "/2"
 ENDIF
 ENDIF
 ENDIF
 ENDIF

Hopefully all the functions (MOD, floor, ITOS) are available in repeat region calculations.