I bought a bunch. This checkered tablet comes in two sizes, A4 and B5. Eraser and pen can be inserted into the slot at the top of the board, which is very convenient. Moreover, this handwriting board writes smoothly, so it should be no problem to teach children math. It's much more convenient than the ordinary handwriting board, and it's not that kind of one-click elimination. You can wipe it wherever you want, and it's not expensive. You can buy it and try it.