Stem-And-Leaf-Diagrams Edexcel Foundation

Stem & leaf diagrams

What is a stem-and-leaf diagram?

• A stem–and–leaf diagram is a simple way to display an ordered list of data using digits

• Two-digit numbers are split into a tens digit (the stem) and a units digit (the leaf)

  • 25 becomes 2 | 5

  • The stem is written vertically and the leaves are written horizontally (in order)

• The following diagram shows the ages below

  • 11, 18, 20, 21, 25, 28, 29, 35, 36, 40

Key: 1|8 means 18 years old

What is the key on a stem-and-leaf diagram?

• The key shows how values are formed from digits

  • It should include units

• Other keys are possible

  • 2 | 5 represents 2.5 degrees

  • 2 | 5 represents 2005 people

How do I find the median from a stem-and-leaf diagram?

• The median is the middle number

  • Data values are already in order

  • You can cross out numbers from the beginning and end until they meet in the middle

    • Remember that the highest number will be at the end of the last stem

    • If two numbers remain in the middle, find the midpoint between them