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Home > Maths I > Relationships > Graphs, charts and tables

Maths I

Graphs, charts and tables

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Stem and leaf diagrams

A maths test is marked out of 50. The marks for the class are shown below:

  • 7, 36, 41, 39, 27, 21
  • 24, 17, 24, 31, 17, 13
  • 31, 19, 8, 10, 14, 45
  • 49, 50, 45, 32, 25, 17
  • 46, 36, 23, 18, 12, 6

This data can be more easily interpreted if we represent it in a stem and leaf diagram.

This stem and leaf diagram shows the data above:

A stem diagram. Along the zero row are the numbers 6, 7, 8. Along the 1 row are the numbers 0 2 3 4 7 7 7 8 9. Along the 2 row are the numbers 1 3 4 4 5 7. Along the 3 row are the numbers 1 1 2 6 6 9. Along the 4 row are the numbers 1 5 5 6 9. Along the 5 row is the number zero. The key at the top says Key 2 5 means 25. This tells you how to read the diagram. 0 and 6 is recordred as zero 6. Number 9 in row 3 is numbers 39.

The stem and leaf diagram is formed by splitting the numbers into two parts - in this case, tens and units.

The tens form the ‘stem’ and the units form the ‘leaves’.

This information is given to us in the key.

It is usual for the numbers to be ordered. So, for example, the row

A stem diagram. The first number is 2, behind a vertical line. Then these numbers follow left to right: 1, 3, 4, 4, 5, 7.

shows the numbers 21, 23, 24, 24, 25 and 27, in order.

Question
From the stem-and-leaf diagram, how many children scored more than 40?
Answer

6 people had a score of more than 40

To find this, look down the 'stem' to the row labelled '4', and don't forget to include the child who scored 50!

A stem diagram. Row 4 has the numbers 1 5 5 6 9 along it. Row 5 has the number 0 along it.
Next

Watch

Bar graph.

Class Clips

Video clip showing how a clothes shop uses graphs to keep track of stock and popular sizes

Watch

A young boy playing in his garden.

Class Clips

And just for fun - become as excited about graphs as this boy with this jolly song...maybe!

Play

A picture of Mia Cadaver

Tombstone Timeout

Swot up your sums with Mia Cadaver's maths game

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