A test site in Japanese, so maybe it would help to know kanji; but all you have to do is click on <Start>, then the screen will count down 3, 2, 1, and then very briefly (for 1 second or less) some numbers will appear arranged randomly on the screen. The numbers disappear and in their formerly held places circles will show instead.
What you have to do is click on each circle in the order of lowest number to highest number. So if 2 was the lowest of numbers shown you'd click on that circle first, and then on every other circle going up in denominations. Sometimes there's only a few numbers/circles, sometimes there's quite a few. At the end, when you've finished all the screens, a big number will flash showing what your "brain age" is. Apparently I've got a 35-year old brain in a 57-year old body. http://flashfabrica.com/f_learning/brain/brain.html Takes just a few minutes.
