Easy way: .7 repeating=7/9.18 repeating=18/99.653 repeating=653/999if you have 4 repeating places, make those four digits into whole numbers and put them over 4 "9"san example worked out: .31313131... X=.31313131... 100x=31.31313131... 100x-x=31 99x=31 x=31/99