Strange Float Screwup

Hi fellas, upon using this code I get a strange result which is beyond my knoweldge to explain.

Global a# = 0

For b = 0 To 125
	a=a+0.05
	Print a
Next

WaitKey()

Please try it, after some amount of increments, the float number of "a" gets a decimal like .0001, why would this happen? Any way to fix this? It's screwing a lightning system I'm working on.

Thanks.