A method of counting and ordering numerical data without losing the detail of the individual data. The last significant digit for the whole data item is determined and each data item is represented by this digit (the leaf), with a stem consisting of the previous digits. For example, 58 is divided as 5|8, with a stem of 5 and a leaf of 8. Only the leaf is shown explicitly on the diagram. A back to back stem and leaf plot can be an effective method of comparing related populations.

Stem and leaf diagram. The data are 22, 58, 12, 17, 4, 26, 10, 13, 1, 39, 0, 1, 10, 6, 0, 11, 14, 1, 0, 7. The diagram retains all the information in the data, while also giving an idea of the underlying distribution.

Back to back stem and leaf plot. The size of eggs laid by cuckoos varies according to the nest being used.