Students take turns drawing match cards and using mental math. Each game is conveniently color-coded and kept organized in the box by matching tabbed dividers. Each Math Stacks game contains a total of 60 cards. Cards measure 3" x 4". Recommended Grade(s): 6-8 The cards are stacked in everyone's favor with Math Stacks! Students take turns drawing match cards and using mental math, look for the equivalent starter card on which to stack it. Once a stack is made, it can be collected. The person with the most stacks at the end of play wins! Each game is conveniently color-coded and kept organized in the box by matching tabbed dividers. Each Math Stacks game contains a total of 60 cards. Some decks includes 20 starter cards and 40 match cards in order to make three-card stacks, while others include 15 starter cards and 45 match cards to create four-card stacks. You can differentiate the level of play by removing unwanted starter cards and their matches. Cards measure 3" x 4". 1 to 4 players. The Classroom Set includes all 6 decks for Grades 6-8 below: Equivalency & Proportional Relationships Geometry Integers Least Common Multiple/Greatest Common Factor One-Step Algebra Two-Step Algebra