Buffon’s needle is a classic Monte Carlo simulation that we can conduct in a classroom.
We give the students, say 10 needles each, and have them drop the needles on a paper that we provide also.
The paper is special, in that it has parallel lines that are separated by the length of a needle.
Each student records how many needles intersect one of the lines, then we tally their numbers to arrive at a very special number. (Guess who ?)