To hone their spatial reasoning, third grade accelerated math students solved polyomino puzzles. They recreated outline designs using only “L” and “I” triominoes. At first some thought the puzzles were impossible to solve, but the children employed the primary mathematical practice of persevering in solving a challenging problem; they eventually solved the puzzles and used their newly developed skills to complete even more complex puzzles. The students will continue to work with a variety of polyominoes to develop their skills of mentally manipulating the shapes, visualizing what the new result will be when a given shape is reoriented and even turned over.