Working it out with nothing left to guess. On most of these boards the arithmetic is deliberately light, so what is left is the reasoning.
Stirring Paint has no arithmetic in it at all: a colour, a direction and a jump for every cell, until each colour closes a single loop. Hitome’s Garden turns on binary choices — every line has exactly two ways to go — which is what makes it deducible rather than merely searchable. Finding Zero and Longest Road are about using an answer you have already paid a turn for. Lozenge Land asks for the fewest blocks that let water reach every floor, and a block only stands where something holds it up. No Three in a Line asks for every line through the towers to be kept in mind at once, the slanted ones too, while the city grows. Minotaur asks for the most steps from a door to the Minotaur, where every step taken decides what the next one may be. Gozen, Zebra and Balanced Zebra put the same reasoning inside a game, where the other side is reasoning too. Voronoi Islands scores you only at the start of your own turn, so every move is judged by what the other colony can do to it first. In Ariadne’s String two threads share one hall, so every step laid is also a wall the other thread has to walk round.