I love these flash cards and so does my first grader! I completely recommend them for several reasons. First, the cards are very stylish with cute colors and large print. I like that the cards have math problems on both sides. The answers to the problems are on the reverse so my oldest son can help showing the cards. Also, the box contains 4 rings that can be inserted in the already perforated cards. This is a great way to keep organized and avoid losing the cards. We have not used the pen to write on the cards because we have a dry erase board that my son prefers to use. Another reason why I'm happy with my purchase is that the 4 flashcard packages (additional, subtraction, multiplication and division) came in a small, compact box that I can use to store all the cards when done using them. But the best reason of all is that my 6 year old loves using them and asks me to look through them daily! He loves these cards so much that he wanted to go through multiplication and division! For me, that makes it worth every penny! Don't look any further, these are the best math flash cards you can buy!