1. Mean, Median, Mode and Range Lesson 1-10 Textbook Pages: 53-58
7th Grade Math
Mean, Median, Mode and Range
Lesson Textbook Pages:
Obj. 5b

2. Central Tendency Mean Median Mode
When you have a “set of data” (or numbers), there are 3 different
ways you can find the center of the data.
Mean
Median
Mode
Let’s look at these 3 different ways to find the center using the following…
Set of Numbers: 2, 3, 1, 1, 0, 1, 2, 4

3. Mean
Mean = Average

4. Divide by the # of items in the dataset.
What is the Mean?
Your report card has an average on it.
The Mean is the average.
2 simple steps will give you the mean of a set of numbers.
Mean = Average
Step 1
Add the numbers.
Step 2
Divide by the # of items in the dataset.

5. Divide by the # of items in the dataset.
Example of Mean:
Step 1
Add the numbers.
Step 2
Divide by the # of items in the dataset.
Set of Numbers: 2, 3, 1, 1, 0, 1, 2, 4
Add the numbers: =
Divide by total items: 14 ÷ 8 =
Mean 14
1.75

6. Median
Median = Middle

7. What is the Median? The Median is the middle number.
How do you find the Median?
Median = Middle
If there is just 1 middle #:
your done!
ORDER
the numbers.
FIND
the middle #.
If there are 2 middle #’s
Average the 2 middle numbers.

8. Example of Median Median Set of Numbers: 2, 3, 1, 1, 0, 1, 2, 4
ORDER
the numbers.
If there is just 1 middle #:
your done!
If there are 2 middle #’s
FIND
the middle #.
Average the 2 middle numbers.
Add the 2 middle numbers
Then, Divide by 2
Set of Numbers: 2, 3, 1, 1, 0, 1, 2, 4
Arrange in order: 0, 1, 1, 1, 2, 2, 3, 4
= 3
3 ÷ 2 =
1.5
Median

9. Mode
Mode = Most

10. What is Mode?
Cokes are popular. There are probably more cokes in this machine than anything else!
The Mode is the number that appears the Most often.
You can have more than 1 mode.
There may be no mode at all!
Mode = Most

11. Example of Mode
Set of Numbers: 2, 3, 1, 1, 0, 1, 2, 4
Mode 1

12. Range
Range = Biggest – Smallest

13. What is the Range? Range = Biggest - Smallest
The Range is not a form of central tendency, but it is another way to get information from a “set of numbers”.
The range describes the spread of the dataset.
The Range is the difference between the biggest number and the smallest number.
Range = Biggest - Smallest
Temperature Range
Michigan: 35 degrees Florida: 75 degrees
Temperature Range was 40 degrees!

14. Example of Range 4 Range = Biggest – Smallest
Set of Numbers: 2, 3, 1, 1, 0, 1, 2, 4
Subtract: 4 – 0 = 4
Range

15. Remember.... Average Median = Middle Mode = Range = Most
Mean =
Median =
Mode =
Range =
Middle
Most
Biggest – Smallest

16. You Try! Mandy’s math test scores: 90, 85, 80, 70, 90, 65
90, 85, 80, 70, 90, 65
Determine the following:
Mean _______
Median _______
Mode _______
Range _______

17. Answers! Mandy’s math test scores: 90, 85, 80, 70, 90, 65
90, 85, 80, 70, 90, 65
Mean __80___
Median __82.5_ (find average of 80 & 85)
Mode __90___
Range __25___
Order the numbers. Mean : Add numbers: Divide by : Answer: ÷ 6 = So, Mean = 80
Median: There are two numbers in the middle. Average: = 165 ÷ So, Median = 82.5
Mode: occurs the most So, Mode = 90
Range: – 65 = So, Range = 65

18. Closure What did we learn today (key words):
Mean = _________________ ?
Median = _________________ ?
Mode = _________________ ?
Range = _________________ ?
Which central tendency requires you to first put the numbers in order?
When finding the median, what do you do if there are 2 middle numbers?
Average
Middle
Most
Biggest – Smallest
Median
Average the two middle numbers by adding them together and dividing by 2.