Say, you have a turn-based game where units move on a grid. … Then you realize that the move finishes exactly when the position of the unit coincides with the target cell’s center.

I mean, something like inbetween(target - cellRadius, target + cellRadius), no?

And of course you first (and generally) convert the floating points to units you can actually work with, why is this even a question? Anyone who knew KSP as more than a rocket explosion simulator, learned that lession long ago from the Kraken.