The math curriculum (Everyday Math) used in the county I teach in is heavy on "slate work." A.k.a. using dry-erase boards. I've seen a lot of the teachers buy those cute little mini erasers from places like Lakeshore, however that can add up quick, and end up relatively "expensive" when there is a cheaper alternative - felt.
(Off topic- do you love my bright, lime green counter tops or what?!)
I had my felt left over from a project I did back when I was first in teacher school, so my erasers where free, however, felt is fairly cheap, and if you buy it off the bolt with a coupon, it's even cheaper. Like a penny an eraser (according to my highly mathematical calculations). They work just as well as store bought erasers and it's no big deal when someone loses one.
My next dry-erase board experiment is dry erase crayons. I saw them on Amazon.com, and my box is due to arrive Tuesday and I'm excited to test them out. I've also heard regular crayons work too. I'll be doing some experimenting, because I'll be honest, I hate dry-erase markers. They are expensive, smelly, the kids are always losing the caps and then they dry out, or are pressing to hard and pushing the points in. I have my fingers crossed that the crayons work.
Have you ever tried dry erase crayons? Please, do tell!