I wanted something relevant that students could work on while I was working with small groups - without having to spend a lot of time on my part organizing. This works well. It was time consuming at first to set up the folders (I laminated), but now that it is done there is very little time on my part required. I teach 4th grade and plan on getting the centers for 4th - 5th next year and starting students on 3-4 at the beginning of the year and switching to 4-5 during the 2nd semester. Now I want to try the one for science and the one for geography.
I love Evan-Moor products and this is another great curriculum supplement. The hands on activities presented in this are perfect for my special education students. It is time consuming to set up all of the centers, but once they are prepared you will have them for many years. The pages are perforated and colorful, and I laminated everything to make it long lasting. Directions are simple and there is an answer key.