Stem and Leaf Plots
A Stem and Leaf Plot is a special table where each data value is split into a stem (the first digit or digits) and a leaf (usually the last digit). Like in this example:
Example:
"32" is split into "3" (stem) and "2" (leaf).
More Examples:
- Stem "1" leaf "5" means 15
- Stem "1" leaf "6" means 16
- Stem "2" leaf "1" means 21
- and so on
The stem values are listed down, and the leaf values go right (or left) from the stem values.
The stem is used to group the scores and each leaf shows the individual scores within each group.
Example: Math Test Scores
Here are the test scores of 9 students:
15, 16, 21, 23, 23, 26, 32, 39, 40
Let's put them into a Stem and Leaf Plot! The tens digit will be the stem, and the ones digit will be the leaf:
| Stem | Leaf |
|---|---|
| 1 | 5 6 |
| 2 | 1 3 3 6 |
| 3 | 2 9 |
| 4 | 0 |
Stem 3, leaf 2 means 32
We can easily see that most students scored in the 20s
Note:
- Include a key like: Stem 3, leaf 2 means 32
- List the stems downwards, in order
- List the leaves along, in order
- It is OK to repeat a leaf value
- 40 has a leaf of "0"
We can use it with decimals as well:
Example: Long Jump
Sam got his friends to do a long jump and got these results:
2.3, 2.5, 2.5, 2.7, 2.8, 3.2, 3.6, 3.6, 4.5, 5.0
And here's the stem-and-leaf plot:
| Stem | Leaf |
|---|---|
| 2 | 3 5 5 7 8 |
| 3 | 2 6 6 |
| 4 | 5 |
| 5 | 0 |
Stem 2 leaf 3 means 2.3
Note:
- Here the stem is a whole number and the leaf is the tenths digit
- 5.0 has a leaf of "0"