Books, books, books, books, books, books, and books! Work by Brian Belott, part of the "book/////shelf" exhibition at the MoMA, photograph by Kenny Louie via Flickr at https://www.flickr.com/photos/kwl/
Estimation Station: "Each week the students get to estimate how many items are in the bag. They choose their number, write it next to their name and then cross it out on the 100 chart. On Friday we count how many items are in the bag and the closest guess gets to take the bag home."