My 6 year old DS came home disappointed that his teacher did not know what he was talking about and asked him to stop being silly when in the math lesson he added two numbers mentally and then gave her 2 answers: one in the decimal system and the other in the base 4 number system just because it seemed like a good thing to do!

I told him that it was OK if the teacher did not know about other number systems and how to convert back and forth between them mentally. I also told him that I was proud that he had this skill and that it would come in handy in his computer science classes whenever he gets to take them!