In this math lesson, learners learn how to construct stem and leaf plots. Learners first estimate the number of drops of water that will fit on the head of a penny. Learners write their guesses on Post-it notes and arrange the notes in a stem and leaf plot. Then, learners conduct the experiment and record the results on Post-its that are displayed on the same stem and leaf plot, thus creating a back-to-back stem and leaf plot. Learners work in groups to analyze the data, paying particular attention to the data range and the extent to which different variables may have contributed to any disparities.