1. To understand how to approach a question about stem and leaf diagrams.
Objectives
To understand how to approach a question about stem and leaf diagrams.
Edexcel GCSE Maths Spec B – Modular: Booster C © Pearson Education 2010. This document may have been altered from the original.

2. The number of people who completed the task The range of times
Question
The number of minutes taken to complete a sorting task are recorded in the following stem and leaf diagram.
3|6 means 36 3 4 5 6 7
3 5
Find:
The number of people who completed the task
The range of times
The median time
The mode
Key 3|6 means 36
Edexcel GCSE Maths Spec B – Modular: Booster C © Pearson Education 2010. This document may have been altered from the original.

3. The number of people who completed the task
Question
The number of minutes taken to complete a sorting task are recorded in the following stem and leaf diagram.
The number of people who completed the task
3|6 means 36 3
(8) 4
(7) 5
(12) 6
(8) 7
(2)
= the number of values in the diagram.
= = 37
Key 3|6 means 36
Frequencies
Edexcel GCSE Maths Spec B – Modular: Booster C © Pearson Education 2010. This document may have been altered from the original.

4. Question
The number of minutes taken to complete a sorting task are recorded in the following stem and leaf diagram.
3|6 means 36 3 4 5 6 7
3 5
b. The range of times
= largest - smallest
= 75 – 31 = 44 seconds
Key 3|6 means 36
Edexcel GCSE Maths Spec B – Modular: Booster C © Pearson Education 2010. This document may have been altered from the original.

5. There are 37 values, so the middle will be:
Question
The number of minutes taken to complete a sorting task are recorded in the following stem and leaf diagram.
3|6 means 36 3 4 5 6 7
3 5
c. The median time
= the middle value.
There are 37 values, so the middle will be:
Key 3|6 means 36
Median = 54 seconds
Edexcel GCSE Maths Spec B – Modular: Booster C © Pearson Education 2010. This document may have been altered from the original.

6. = the value that comes up most often.
Question
The number of minutes taken to complete a sorting task are recorded in the following stem and leaf diagram.
3|6 means 36 3 4 5 6 7
3 5
d. The mode
= the value that comes up most often.
This is the largest run of the same number.
Key 3|6 means 36
Mode = 56 seconds
Edexcel GCSE Maths Spec B – Modular: Booster C © Pearson Education 2010. This document may have been altered from the original.

7. Remember that you must subtract when finding the range.
Summary
Remember that you must subtract when finding the range.
When reading values from the diagram it’s very important to remember that you have to put the ‘leaves’ and ‘stems’ together to get 2-digit numbers.
Edexcel GCSE Maths Spec B – Modular: Booster C © Pearson Education 2010. This document may have been altered from the original.