To make a class set, you will need four poster boards ($2) and Chalk Board Spray Paint ($8), both commonly available. You can also use foam poster board. Coat the poster boards in overlapping rows. The first coat should be very thorough. Let it dry completely. Add 2 additional light coats, letting each coat dry completely before adding the next. Finally, cut each poster board into 6 equal rectangles. Wa-LA! I am amazed at how beautifully the chalk is erased!
I love how thin and lightweight these are for younger children to store and use. They fit perfectly in an inside pocket we create in their math journal. Also, chalk is inexpensive and never goes dry like dry-erase markers inevitably do. A little piece of felt, an old sock, or a craft pom pom make great erasers. The chalk boards can be cleaned with a damp paper towel.
q Diane r