A focused Grade 6 learning session for Stem-and-Leaf Plots using visual models, worked examples, strategy guidance, and a short mastery check.
Student goal: I can solve problems involving stem-and-leaf plots.
Stem-and-Leaf Plots means reading, creating, and explaining displays so data can answer real questions.
Question: The stem-and-leaf plot below shows the heights (in cm) of students in a class. What is the minimum height?
| \multicolumn{1}{c|}{Stem} | \multicolumn{1}{c}{Leaf} |
|---|---|
| 14 | 0, 2, 5 |
| 15 | 1, 4, 8, 9 |
| 16 | 3, 6, 7 |
| 17 | 2, 5 |
Why it works: The smallest value in the plot is found by taking the smallest stem (14) with its smallest leaf (0), giving \(140\) cm.
Answer: \(140\) cm
Question: A stem-and-leaf plot of student test scores is given: What is the mode of the test scores?
| \multicolumn{1}{c|}{Stem} | \multicolumn{1}{c}{Leaf} |
|---|---|
| 6 | 5, 8 |
| 7 | 1, 3, 4, 6, 9 |
| 8 | 0, 2, 5, 7 |
| 9 | 1, 4, 8 |
Answer: No single mode
Question: A fitness coach records the number of push-ups done by \(11\) athletes: Which interval contains the most data points?
| \multicolumn{1}{c|}{Stem} | \multicolumn{1}{c}{Leaf} |
|---|---|
| 2 | 3, 5, 8, 9 |
| 3 | 1, 4, 6, 7 |
| 4 | 2, 5, 8 |
Answer: Both have equal counts
Question: Raw data for number of books read by 8 students: \(12, 18, 15, 12, 20, 15, 14, 19\). If you were to create a stem-and-leaf plot, how many leaves would be in stem \(1\)?
Why it works: Numbers in the 10s: \(12, 18, 15, 12, 20, 15, 14, 19\). Those with stem \(1\): \(12, 18, 15, 12, 15, 14\) (6 values).
Answer: \(6\) leaves
Stem-and-Leaf Plots becomes easier when students connect the question to a model, use clear steps, and explain why the answer fits.
Read the scale before reading the answer.
Use scratch paper. The explanation matters more than simply seeing whether the choice is correct.
A stem-and-leaf plot of test scores has stem \(7\) with leaves \(2, 5, 8\). Which values are represented?
Answer B: \(72, 75, 78\)
In a stem-and-leaf plot, each leaf combines with the stem to form a value. Stem \(7\) with leaves \(2, 5, 8\) represents \(72, 75, 78\).
The stem-and-leaf plot below shows the heights (in cm) of students in a class. What is the minimum height?
Answer A: \(140\) cm
The smallest value in the plot is found by taking the smallest stem (14) with its smallest leaf (0), giving \(140\) cm.
Using the same stem-and-leaf plot from Question 2, what is the maximum height?
Answer C: \(175\) cm
The largest stem is 17, and the largest leaf for that stem is 5, so the maximum is \(175\) cm.
Using the same stem-and-leaf plot from Question 2, what is the range of heights?
Answer A: \(35\) cm
Range = Max \(-\) Min = \(175 - 140 = 35\) cm.
A stem-and-leaf plot shows daily temperatures (in \(°\)F) recorded during winter: How many temperatures are recorded?
Answer C: \(10\)
Count all leaves: \(3 + 4 + 3 = 10\) data points.
Using the temperature data from Question 5, what is the median temperature?
Answer A: 45°F
Order the data: \(32, 35, 39, 41, 44, 46, 48, 50, 53, 57\). With \(10\) values (an even count), the median is the average of the \(5\)th and \(6\)th values: \((44 + 46) \div 2 = 45°\)F.
Using the temperature data from Question 5, which temperature appears most frequently (the mode)?
Answer A: No mode
Each temperature appears exactly once in the data, so there is no mode (or all are modes).
A stem-and-leaf plot of student test scores is given: What is the mode of the test scores?
Answer D: No single mode
Each stem has multiple leaves but no single score repeats more than once, so there is no single mode.
In the stem-and-leaf plot above (Question 8), how many scores are in the 70s?
Answer C: \(5\)
Stem \(7\) has leaves \(1, 3, 4, 6, 9\), which is \(5\) leaves total.
Raw data for number of books read by 8 students: \(12, 18, 15, 12, 20, 15, 14, 19\). If you were to create a stem-and-leaf plot, how many leaves would be in stem \(1\)?
Answer B: \(6\)
Numbers in the 10s: \(12, 18, 15, 12, 20, 15, 14, 19\). Those with stem \(1\): \(12, 18, 15, 12, 15, 14\) (6 values).
A fitness coach records the number of push-ups done by \(11\) athletes: Which interval contains the most data points?
Answer C: Both have equal counts
Count the leaves on each stem: stem \(2\) (the 20s) has \(4\) leaves, stem \(3\) (the 30s) has \(4\) leaves, and stem \(4\) (the 40s) has \(3\) leaves. Stems \(2\) and \(3\) are tied for the most data points, so the correct response is that both intervals have equal counts.
