Whether you are looking to improve your childrens math skills to complement what they are learning in school or to give them a head start, our parent testers felt strongly that the 681 Math Flash Cards Bundle were the absolute best math flash cards on the market. That’s some pretty high praise, but it wasn’t just a few testers. Across the board, we received review after review singing the praises of this educational powerhouse. The cards are brilliantly designed. There are three inserts to assist parents using the system – “Don’t Know Yet,” “Sort of Know,” and “Mastered.” This sorting method helps you most effectively gauge your childs progress. The back sides of the cards display the answer along with a superb visual breakdown which explains the answer using very simple cubes and charts. This helps children not only to memorize the answer but truly understand the process used to ascertain the solution so they can go back to it again and again. These cards will grow with your children, they start with addition, then subtraction, and will eventually move into multiplication and division. Parents were impressed by the quality, the packaging and even the boxes that hold the thick and sturdy cards. They described it all as both attractive and sturdy enough to stand the test of time. These cards should easily pass from child to child and would also be an excellent addition to any classroom.