Don’t Lose Your Marbles—Are You Coming or Going? Student Activity Divide into teams as instructed by your teacher. The steps in this activity are written as if you have divided up into teams of three members. Each team should have a “source” person, a “timer/recorder,” and a “receiver.” Your teacher will provide a track on which you will roll marbles from the top to the bottom. Obtain approximately twenty marbles and a stopwatch from your teacher. For Trial One, the “source” person should place the marbles on the track at even, approximately one-second intervals. The “receiver” collects the marbles as they arrive at the end of the track, announcing the arrival of the first and the last marble. The “timer/recorder” uses a stop watch to measure the time of arrival and of the first and the last marble at the end of the track and records the time on the Reporting/Data Sheet. As a team, calculate the frequency of the rolling marbles. The frequency equals the number of marbles “received” divided by the time in seconds. For Trial Two, repeat the process with the following change. As soon as the first marble arrives at the end of the track, the “receiver” should slowly, taking “baby steps," begin to walk toward the source, collecting from the track all the marbles that pas by him/her for a ten-second period. The “timer/recorder” should call out the time. Count the marbles and record the results on the Reporting/Data Sheet. As a team calculate the frequency for the marbles collected by the moving “receiver.” For Trial Three, repeat the process with the following change. This time, the “receiver” should stand near the “source.” As soon as one marble passes by, the “receiver," should slowly walk down the track collecting from the track all the marbles for a ten-second period. The “timer/recorder” should call out the time. Count the marbles and record the results on the Reporting/Data Sheet. As a team calculate the frequency for the marbles collected by the moving “receiver.”