As kids put together our skill-building sun puzzles, they boost addition fluency—in a concrete, visual way! Each self-correcting puzzle features a number from 1 to 20, plus 5 equation pieces. Kids just match the number in the sun’s center to the corresponding equations—developing addition fluency with instant reinforcement! Each set includes 17 puzzles divided into 4 skill levels that gradually progress in difficulty. Complete set includes all 3 sets shown, for a total of 51 puzzles. Puzzles measure 6". Each set also available separately.