Use these math-fact triangles again and again! Familiar triangle format offers a powerful method for building number fact fluency and teaching fact families. Focuses on both addition/subtraction (on front side) and multiplication/division (on reverse). Supports development of higher-level algebraic skills such as equation building, the commutative property and problem solving. Write & wipe surface on both sides of the board. Triangle boards measure 10"H. Grades 1+. Each set includes 5 boards. Sold as 2 sets for a total of 10 boards.