Award-winning, color-coded learning system helps teachers make math lessons fun! Cards are color coded by number families. Self-checking answers on back. Predrilled holes for storage on included sort-and-store rings. Each set includes 169, 2-1/2" x 5" cards. Aligned with Common Core and State Standards. Supports requirements of Title I and other federally funded programs. Sold as a pack of 2 sets of cards.