Content-rich math cards do their job, teaching students new skills in a fun way. This educational aid develops basic addition skills 13-18. Self-checking, answers on card backs. Sturdy cards and storage box. Students will delight in mastering new skills. No-see-through cards with quick-sorting, rounded corners. Details: Black & white cards3" x 6"Includes 1 box of 99 cardsFurther develop addition skills, practicing 13-18Great for test prep and reviewSelf-checking, with answers on card backsSturdy tagboard cards and reinforced cardboard storage boxIdeal for teaching ages 6 and up