This printable math center is a fun way of teaching kids time to the half hour! There are a variety of ways to implement these cards. One way is: after you print, cut the cards (and laminate if you wish), and place them all face down. Then students play as a memory/concentration - where getting a pair requires matching the analog clock card to the digital clock card. You can also distribute, and have them play Go-Fish. Another way of using these cards are to print, cut, and paste together and have students use as flashcards. My first and second graders LOVED playing with these in math centers. This set comes with 20 cards (10 pairs) total.