Is "chocolate" countable or uncountable?

Ok, I teach English as a foreign language and am teaching my kids about countable versus uncountable right now. Chocalate itself is normally considered uncountable. In you example you have a "bar of chocolates" and a "box of chocolates" Boxes and bars are countable nouns. Chocalate itself isn't countable so we need a measutring word such as piece, box, or bar.