Stem and Leaf Diagrams - GCSE Maths Definition

A stem-and-leaf diagram is a statistical diagram that presents data values in a way that can be easy to analyse and draw conclusions from, whilst maintaining the raw data. Stem-and-leaf diagrams are usually used with two-digit data, but can be used with three-digit data, as long as this is made clear by the use of a key.

A stem-and-leaf diagram is best demonstrated by an example

Key: 4 | 4 represents 4.4

The main features from this stem-and-leaf diagram are

• the data is grouped - there are four values in the class interval 2 ≤ x < 3 - these are 2.1, 2.3, 2.5 and 2.6

• the data is ordered, so we can quickly find the median (4.4), the range (6.3 - 2.1 = 4.2)

• all the raw data values are still shown - starting with 2.1, 2.3, 2.5, ... and ending with 5.8, 6.1 and 6.3

Stem-and-leaf diagrams are simple to construct and easy to read. The key is crucial to understanding the values being shown and should always be included if you are asked to draw a stem-and-leaf diagram in your GCSE Mathematics exam.