Clock of Nines

Math enthusiasts who don't want to move totally into the digital realm might appreciate this analog clock.

Each number is expressed as a calculation involving three instances of the number 9.

For example, 5 o'clock is the square root of nine (3), factorial (3x2x1 = 6), minus 9/9 (6-1 = 5).

The trickiest time is 7 o'clock, whose calculation works out to 6.99999..., with an infinite number of nines. Wikipedia assures us that 0.99999... really does equal 1, so no worries that the clock is cheating there.

[Via News.com]