Trend® Skill Drill Flash Cards. Addition 0-12 skill drill flash cards are great for practicing and mastering addition to build a solid math foundation, prepare for higher-level concepts and boost student confidence and learning success. Practice math with 91 self-checking addition cards. Activity ideas are included to keep kids engaged and challenged in classrooms, homeschools, learning centers, and more. Cards show equations on one side and answers on the other. 91 flash cards included, 3" x 6" each.