If I shared this anywhere else but here, I'd get shunned by our community for certain.

My son and his teacher come out of his classroom together one afternoon a few months back (3rd grade) and the teacher says, "Your son taught the class about the square root of negative one today!" My son brought it up when they were working with the series of squares on the multiplication table.

Another child asked about taking the square root of -4 (or something like that) and the teacher demonstrated on her calculator that it would result in an error... just like dividing by zero.

Well... not only was my guy confident (brave? stupid?) enough to contradict the teacher, but also willing to bet against the calculator.

On a lark, he and I had discussed it a few weeks earlier when he was practicing math with negative numbers. No, he didn't figure it out on his own (that would be REALLY scary), but he did fully grasp the concept and can use it in simple problems like (2i)^2 = -4 and so forth.

The teacher said she'd forgotten all about it and was tickled at being reminded by a 3rd grader.

I'm still constantly amazed at what he can process.
Being offended is a natural consequence of leaving the house. - Fran Lebowitz