I like it a lot, was looking for something like this to teach 13 with, so, thanks! Had trouble editing values in the tiles tho - backspace made the browser go

I like it a lot, was looking for something like this to teach 13 with, so, thanks! Had trouble editing values in the tiles tho - backspace made the browser go back to HN and delete had no effect. This was in the most recent chrome on my ubuntu machine. Is there another way?