Intuitively develop children's understanding of how words work, and how words follow predictable patterns. Other patterns include ai, ay, ea, ou, ck, and so on. For an extra challenge, the words can be listed in columns by number of letters in the word. Or use a timer to see how man words they can find in just three minutes! Build words mentally with just paper and pencil, or physically with plastic letter tiles (not included). 22 puzzles with 6- and 7- letter words. 20 books per set.