The idea behind the center board is it is a way for students to see a display and make a choice of what center they want to do. It also creates an easy system that they can help me switch out when the letter changes. Once I train them to, they know what to do each week for the letter. Finally, having the materials right there to pull off the board, makes it easy for them to grab exactly what they need to do for the center. The whole thing is an interactive organized experience!!! Each kind of center has a center for EVERY letter! So you end up with 6 centers for each letter, which comes to a total of 156 CENTERS! Yes it is a lot, but it is everything you need for the alphabet for a year when it comes to centers. Completely interactive and no worksheets! Each center comes with explanations on how to put them together and what pieces you may need to get (ie building blocks, clothes pins).