Lesson 7: Measures of Center
Finding the middle ground: Mean, Median, and Mode.
🎯 Learning Intentions
- Calculate mean, median, and mode
- Understand which measure is best for different situations
- Analyze data range (spread)
1. The Human Mean (10 mins)
Activity: Give 5 students different numbers of blocks. Ask them to "share them out until everyone has the same amount" without removing any blocks.
Explain: That final number is the Mean (Average).
2. Definitions & Practice (20 mins)
Work through examples with a simple data set (e.g., 2, 5, 5, 8, 10):
- Mean: Add all up, divide by count. (30 ÷ 5 = 6)
- Median: The middle number when sorted. (5)
- Mode: The most common number. (5)
- Range: Highest minus Lowest. (10 - 2 = 8)
Tip: "The Median is the bump in the middle of the road." "Mode is the Most."
3. Application (15 mins)
Look at your own investigation data:
- If you have category data (e.g., Red, Blue), you can only find the Mode.
- If you have number data (e.g., heights), you can calculate Mean, Median, and Range.
Task: Calculate relevant measures for your data.
4. Discussion (5 mins)
Why might the Mean be misleading if there is one huge outlier?
(e.g., If billionaire joins our class, the "average" wealth skyrockets, but median stays same.)