Power up essential skills with this handy pack of our most popular flash cards. Fun games, rich in content, big in results. Introduce, practice, and master addition sums to 9, rhyming with words/pictures, math problems covering charts, algebra, and graphs, and spelling and vocabulary. Self-checking, answers on backs. Quick-sorting, no-see-through cards. Two-sided, 3.5" x 5.25" cards.