Pythagoria is a puzzle game for PCs. It’s the same idea as Naoki Inaba’s Area Maze: you’re shown a geometric construction, not drawn to scale, and you have to work out a missing length or an area.
Each puzzle is constructed so that it can be solved without ever dealing with fractions, though what exactly that means is up for debate. Whatever it means, it keeps you from breaking out pen and paper to solve a problem algebraically, when you know there should be a way of doing it in your head.