[thewanderer1983]

You can actually estimate this pretty well with only your brain and basic math. Example 1 in Guesstimation by Lawrence Weinstein and John Adams, would work for this problem. The problem is about estimating the height of all lottery tickets in a lottery. Another book called The art of Insight in Science and Engineering by Sanjoy Mahajan has this problem (1.3) but its with a suitcase filled with $100 bills.