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Stem-and-Leaf Plots
Chapter 6
Algebra 1
Ms. Mayer
Stem-and-Leaf Plot
Uses place value to organize data
Shows data in an organized way so it can be analyzed easily
Organizes data so it is easier to find the median, mode, and range
Stem-and-Leaf Plots: A convenient method to display every piece of data by showing the digits of each number.
How to Draw One:
1. Put the first digits of each piece of data in numerical order down the left-hand side
2. Go through each piece of data in turn and put the remaining digits in the proper row
3. Re-draw the diagram putting the pieces of data in the right order
4. Add a key
Stem-and-Leaf Plot
Here are the scores for a
freshman basketball team
Here is the same data organized into a stem-and-leaf plot.
Can you tell how the stem-and-leaf plot was made?
The first number in the data is 27.
Here is the 2 in the tens place.
Here is the 7 in the ones place.
The key shows us which place value the digits represent.
The stems all represent tens place in this stem-and-leaf plot. The leaves all
represent ones.
Let’s try one together…
Here are one student’s math test scores. Make a stem-and-leaf plot for this data.
First, draw the dividing lines.
Here are one student’s math test scores. Make a stem-and-leaf plot for this data.
Next, label the stem side and the leaf side. Stems Leaves
Here are one student’s math test scores. Make a stem-and-leaf plot for this data.
Find the smallest piece of data and plot it on the grid.
Stems Leaves 7 5
Here are one student’s math test scores. Make a stem-and-leaf plot for this data.
Find the next smallest piece of data and plot it on the grid.
Stems Leaves
7 5 9
The 7 for the tens place is already there. We just add the 9.
Continue with this process until you have entered all the data.
Stems Leaves 7 5 9
8 3 4 6 6 8
9 1 4 9
Remember to add a title.
Stems Leaves 7 5 9
8 3 4 6 6 8
9 1 4 9
Test Scores
Don’t forget the key!
Stems Leaves 7 5 9
8 3 4 6 6 8
9 1 4 9
Test Scores
Key: 7 5 means 75
You just completed a
stem-and-leaf plot!
Now, try it on your own…
This table shows the times in seconds and hundredths of seconds for the women’s 500-meter speed-skating competition in the 2002 Winter Olympics.
Use this data to make a stem-and-leaf plot.
2002 Winter Olympics 500-Meter Speed-Skating Times in Seconds
Check your work…
2002 Winter Olympics 500-Meter Speed-Skating Times in Seconds
Using Stem-and-Leaf Plots
What was the least number of cookies sold?
Boxes of Girl Scout Cookies Sold by Troop 220
40 boxes
Using Stem-and-Leaf Plots
What was the largest number of cookies sold?
Boxes of Girl Scout Cookies Sold by Troop 220
94 boxes
Using Stem-and-Leaf Plots
Find the median of the data
Find the middle leaf…
63 boxes
Boxes of Girl Scout Cookies Sold by Troop 220
Using Stem-and-Leaf Plots
Find the mode of the data Look for the number that occurs
most often in a row of leaves
63 boxes
Boxes of Girl Scout Cookies Sold by Troop 220
Remember:
- Always put in a Key
- Always put your data in Order
Median:
- to work out the median, you must find the middle value
- if there are two middle values, you need the average
Range:
- to work out the Range, subtract the smallest number from the biggest
Stem-and-Leaf Plots
Stem-and-Leaf Plots
The End!
