*[Feature photo above by Tobias Wolter (CC-BY-SA-3.0) via Wikimedia Commons.]*

Here’s a blast from the *Let’s Play Math!* blog archives: Seven years ago, our homeschool co-op held an end-of-semester assembly. Each class was supposed to demonstrate something they had learned. I threatened to hand out a ten question pop quiz on integer arithmetic, but instead my pre-algebra students voted to perform a skit. I hope you enjoy…

If seven people meet at a party, and each person shakes the hand of everyone else exactly once, how many handshakes are there in all?

In general, if

npeople meet and shake hands all around, how many handshakes will there be?## Cast

1-3 narrators

7 friends (non-speaking parts, adjust to fit your group)## Props

Each friend will need a sheet of paper with a number written on it big and bold enough to be read by the audience. The numbers needed are 0, 1, 2, 3, … up to one less than the number of friends. Each friend keeps his paper in a pocket until needed.

*[Click here to go read the original post.]*

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