Pic of the Day

Mental Arithmetic in the Rachinsky School - Nikolay Bogdanov-Belsky - 1895

The problem on the board is (10² + 11² + 12² + 13² + 14² ) / 365. The answer is 2.       (highlight to reveal the answer). Kind of a cute little problem. I didn't notice the problem on the board at first, I thought it was just a cool picture, but then I started looking around and mathoverflow pointed out the problem on the board.

Via Starts with a Bang!

P.S. I made the superscript exponents using the html <sup> tag. I originally tried using the html code I found on mathoverflow, but the html was like four pages long and I couldn't make head or tails of it. PeggyK, a Platinum Product Expert, gave me a clue.