0.78/3.51 = 0.222
The 0.222 repeats on forever, but writing it to the thousandths spot is generally an acceptable spot to stop writing the repeating number. If you're writing it on paper, put a line above the last number (or sets of numbers) that repeats. So, in this case, the last 2 in 0.222 would have a line above it, kind of like an upside-down underline, I guess.
