Round Infinity Number on While Condition

Hi, I need help, when I use the while condition for a thread interpolation in the Fanuc 18i command, if the division obtains an infinite number, the command automatically rounds up causing an interpolation step to be ignored.
Is it possible to calculate without rounding?
Below are the command lines:

G0Z3
#701=0(Z HOME)
#702=[25/2](INITAL DIAMETER)
#703=[27/2](THREAD DIAMETER)
#704=26(Z DEPTH)
#705=2(THREAD STEP)
#706=3(STEPS)
#707=[[#702-#703]/#706](X INCREMENT)
#100=#704
G1Z#701F#771
WHILE[#702LE#703]DO1
G1G42D40X#702
G91
WHILE[#100GT0]DO2
G02I-#702Z-#705
#100=#100-#705
END2
#100=#704
G1G40X-#702
G90
G0Z#701
#702=#702+#707
END1

Ps.: Sorry for the bad English