Stem-and-Leaf Plots

1. Stem-and-Leaf Plots Chapter 6 Algebra 1 Ms. Mayer

2. 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.

3. Stem-and-Leaf Plot How to Draw One: 1.Put the first digitsof each piece of data in numerical orderdown 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

4. Here are the scores for a freshman basketball team • Here is the same data organized into a stem-and-leaf plot.

5. 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.

6. The key shows us which place value the digits represent.

7. The stems all represent tens place in this stem-and-leaf plot. The leaves all represent ones.

8. Let’s try one together…

9. Here are one student’s math test scores. Make a stem-and-leaf plot for this data. First, draw the dividing lines.

10. 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

11. 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

12. The 7 for the tens place is already there. We just add the 9. Here are one student’s math test scores. Make a stem-and-leaf plot for this data. Stems Leaves 7 5 9 Find the next smallest piece of data and plot it on the grid.

13. 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

14. Remember to add a title. Test Scores Stems Leaves 7 5 9 8 3 4 6 6 8 9 1 4 9

15. Key: 7 5 means 75 Don’t forget the key! Test Scores Stems Leaves 7 5 9 8 3 4 6 6 8 9 1 4 9

16. You just completed a stem-and-leaf plot!

17. Now, try it on your own…

18. 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.

19. Use this data to make a stem-and-leaf plot. 2002 Winter Olympics 500-Meter Speed-Skating Times in Seconds

20. 2002 Winter Olympics 500-Meter Speed-Skating Times in Seconds Check your work…

21. Boxes of Girl Scout Cookies Sold by Troop 220 Using Stem-and-Leaf Plots • What was the least number of cookies sold? 40 boxes

22. Using Stem-and-Leaf Plots Boxes of Girl Scout Cookies Sold by Troop 220 • What was the largest number of cookies sold? 94 boxes

23. Using Stem-and-Leaf Plots Boxes of Girl Scout Cookies Sold by Troop 220 • Find the median of the data Find the middle leaf… 63 boxes

24. Using Stem-and-Leaf Plots Boxes of Girl Scout Cookies Sold by Troop 220 • Find the mode of the data Look for the number that occurs most often in a row of leaves 63 boxes

25. Stem-and-Leaf Plots 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

26. Stem-and-Leaf Plots The End!