Object: A stopwatch.

Good morning, boys and girls. How fast can you run? (Let them answer.) Have you ever had anyone time you in a race with a watch? (Let them answer.) I brought with me a very special watch this morning. It is called a stopwatch, and people use it to find out who the fastest runner is in a race, or how fast anyone is when they just want to run around the block all by themselves. A stopwatch can be started at the beginning of a race and stopped at the end of a race.

Let's pretend that we are going to have a race among all of us, to find out who the three fastest people are, so that they can race against each other in one big final race. I could time each one of you as you run around the block and then pick the three fastest o…