We've noticed a strange trend these past few years. Americans have been spelling "ax" with an "e" at the end. Although "axe" isn't incorrect, find out why "ax" is the preferred American spelling here (Page 15): http://tinyurl.com/oht9nyn.
tend to look slightly “cleaner” and last more permanently than chalk. – Scissors or a knife for sharpening if you opt to use classic chalk. (Proceed with extra care!) – A Magic Eraser. The Magic Eraser completely erases any marks, mistakes, or chalk residue. – A piece of scratch paper cut to the size of your chalkboard for spacing practice