Math and Logic Puzzles for Kids: Puzzles for Kids: Sun and Moon Puzzles - 200 Logic Grid Puzzles With Answers (Paperback)

Sun and Moon ("Munraito") is a logic puzzle invented by Naoki Inaba (Japan). A square grid contains planets in some cells. The goal is to place exactly one star and one stardust cloud into each row and each column of the grid. If a particular semicircle of a planet is illuminated, there must be a star in that rank to light it. A star shines horizontally and vertically only; planets and stardust clouds block starlight.