One night recently I woke up and could not go to sleep again. I decided to distract my brain with some mental math and try to trick myself into going back to sleep. The calculation came naturally to mind since the product would be the number of days I was alive on my 67th birthday. Here is the series of calculations that I performed.
Later I checked my answer of Wolfram Alpha (It will calculate the difference between two dates). It was . Exactly right. And no I still couldn’t go back to sleep so I got up and read for a couple of hours.