What is a stem-and-leaf plot?

A stem-and-leaf plot is a method for visualizing data in which the tens digits of the data points are written in a column and the ones digits are written in rows next to them. The tens digits form the stem, and the ones digits are the leaves.

For data values in the hundreds or thousands, the largest digit is put in the stem with the remaining digits are put in the leaves. A stem-and-leaf plot is similar to a histogram but contains the exact value of every data point. Stem-and-leaf plots are therefore useful for determining common statistical metrics such as the mode and median.