I bought a set of Iwako erasers a few years ago for helping my pupils learn the position of the notes on the piano. However, they were such a success, that I bought more of them to use. I always let the pupil get the box of erasers themselves and then I give them the opportunity to choose one for themselves and one for me. The ones that I have bought mostly fit well on an individual key of the piano. It's always a fun way to finish a lesson with a short game that reinforces a concept that the pupil has been learning in the lesson or during previous lessons.
