Stem and leaf plots are typically taught to children in the fifth or sixth grade. This simple method of organization helps prepare students for more complex methods of data plotting. Students must first understand what a stem and leaf plot is and their purpose. Select a data set that's simple for students to understand, such as a group of test scores or the height of students in class. Using a prepared note sheet and the classroom projector or overhead, instruct students to follow along and copy the example set of data.
A simple example is a fictitious sample of test scores. List them in a row, separated by commas. Five to 10 are enough for an initial example. Putting scores out of order helps students see the need for a method of organization to analyze results. When students are finished copying, demonstrate setting up a stem and leaf plot. A blank plot included on the student worksheet can save time and confusion. Label the two columns above the horizontal line. Name the left side of the vertical line "stem" and the right side "leaf."
In the column labeled "stem," instruct students to write the numbers 1 through 10 vertically, in numerical order. Explain that these represent the tens value of the test scores in the example. The first digit in each number is the tens value, representing the number of tens making up that score. In the score 85, 8 is the tens value. Pause, checking for understanding while clarifying student questions. Demonstrate how the numbers are now plotted beneath the "leaf" section. List the corresponding ones value to the right of each stem value. For example, if a test score is 65, the number 5 should be placed to the right of the stem value 6. Instruct students to complete the remainder of the example plot while checking their work. Reinforce and clarify with a second example if students have difficulty.
Contact the computer lab in advance, reserving space for a reinforcement activity. Depending on whether the school uses traditional 40-minute periods or block scheduling, this can make up the second portion of class or be used as a follow-up lesson. Create a sheet of instructions for student use to enable independent learning. "Wisc-Online," referenced below, is an illustrated lesson demonstrating the proper use of stem and leaf plots. Allow students time to review what they learned. Monitor progress while redirecting students who are off task. Activate learned knowledge using the "Interactivate: Stem and Leaf Plotter" referenced. Instruct students to find a set of data online and plot it using the tool. Help students brainstorm possible data sets if they have trouble.
Monitor student progress and understanding during the remaining time in the computer lab. If students finish their assigned work early, allow them to begin their homework assignment. This could involve textbook pages or further examples, using the online examples and tools. Align homework concepts with those demonstrated during the lesson and reinforcement activity. Ask for questions and clarify any lingering confusion about stem and leaf plots.
Check completed homework at the beginning of the following lesson. Go over correct answers to the assigned problems, helping students understand any mistakes in their work. Check for comprehension and ask for any further questions about constructing stem and leaf plots. If students continue struggling with the concept, further reinforce the method using another easily understandable example. Offer after-school help to students still having difficulty.