# Stem and leaf diagrams

A stem and leaf diagram is one way of grouping data into classes and showing the shape of the data.

## Example

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

This is all the information that you require, but it is difficult to interpret. For example, is it easy to tell whether more children got marks in the s than the s? Can you tell at a glance what the highest mark was, or whether more than one person achieved the same result?

One way to represent the data so that you can answer these questions at a glance is in a stem and leaf diagram. This diagram shows the same results as the example above:

• 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 in the key.

The numbers are usually ordered, so the row:

shows the numbers , , , , and in order.

Question

Using the stem and leaf diagram above, answer the following questions.

Q1. How many children scored ?

Q2. What was the most common score?

A1. You can work this out by looking at the column in the tens:

Therefore children score .

A2. You can work this out from the stem and leaf diagram below:

Therefore is the most common score.

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