Interpret stem-and-leaf plots

key notes:

1️⃣ What is a Stem-and-Leaf Plot?

  • A stem-and-leaf plot is a way to organize numbers so we can see them clearly.
  • The stem represents the tens place (or higher place value).
  • The leaf represents the ones place (or last digit).
  • Example: 43 → Stem: 4, Leaf: 3 📝

2️⃣ How to Read a Stem-and-Leaf Plot 👀

  • Look at the stem first → it tells you the group of numbers.
  • Look at the leaves → they tell you the exact numbers in that group.
  • Example:
Stem | Leaf
 4   | 2 5 7
  • Numbers: 42, 45, 47 ✅

3️⃣ Things You Can Find from a Stem-and-Leaf Plot 📊

  • Smallest number 🌱
  • Largest number 🌳
  • Range (largest – smallest) ➖
  • Most common number (mode) ⭐
  • Pattern or trend 📈

4️⃣ Tips to Remember 💡

  • Each leaf is a single digit.
  • No number is left out; all numbers must appear.
  • Arrange leaves in order from smallest to largest. 🔢
  • Always check the stem to know the tens place.

5️⃣ Quick Example 🌈

Stem | Leaf
 2   | 1 3 5
 3   | 0 4 7
  • Numbers: 21, 23, 25, 30, 34, 37
  • Smallest: 21 🌱
  • Largest: 37 🌳
  • Range: 37 – 21 = 16 ➖
  • Mode: No repeat numbers ❌

💡 Fun Tip: You can make your own stem-and-leaf plot using your age of friends, scores, or even your favorite candies! 🍬🎂

Learn with an example

1) At a candy factory, butterscotch candies were packaged into bags of different sizes.

Butterscotch candies per bag
 Stem  Leaf 
3     3 8 9
4     4
5     1
6     0 4
7    
8    
9     0

How many bags had fewer than 94 butterscotch candies?

  • 6
  • 4
  • 8
  • 7
  • Count all the leaves in the rows with stems 3, 4, 5, 6, 7, and 8.
Butterscotch candies per bag
 Stem  Leaf 
3     3 8 9
4     4
5     1
6     0 4
7    
8    
9     0
  • In the row with stem 9, count all the leaves less than 4.
Butterscotch candies per bag
 Stem  Leaf 
3     3 8 9
4     4
5     1
6     0 4
7    
8    
9     0
  • You counted 8 leaves, which are blue in the stem-and-leaf plots above. 8 bags had fewer than 94 butterscotch candies.

2) A food magazine published a listing of local restaurant ratings.

Restaurant ratings
 Stem  Leaf 
1     2 8
2     2 5 9
3     0 1 3 5 6 8
4     3 7
5     0

How many restaurants were rated fewer than 35 points?

  • 7
  • 8
  • 5
  • 6
  • Count all the leaves in the rows with stems 1 and 2.
Restaurant ratings
 Stem  Leaf 
1     2 8
2     2 5 9
3     0 1 3 5 6 8
4     3 7
5     0
  • In the row with stem 3, count all the leaves less than 5.
Restaurant ratings
 Stem  Leaf 
1     2 8
2     2 5 9
3     0 1 3 5 6 8
4     3 7
5     0
  • You counted 8 leaves, which are blue in the stem-and-leaf plots above. 8 restaurants were rated fewer than 35 points.

3) A researcher recorded the number of cows on each farm in the county.

Cows per farm
 Stem  Leaf 
1     1 1 2 2 7
2     7
3     1 3
4     2 2
5    
6    
7     0 1 5 8
8     0 3 4 5 6 9
9     0 0

What is the smallest number of cows?

  • 7 cows
  • 11 cows
  • 10 cows
  • 9 cows
Cows per farm
 Stem  Leaf 
1     1 1 2 2 7
2     7
3     1 3
4     2 2
5    
6    
7     0 1 5 8
8     0 3 4 5 6 9
9     0 0
  • Look at the first row of the stem-and-leaf plot. The first row has the lowest stem. The stem for the first row is 1.
  • Now find the lowest leaf in the first row. The lowest leaf is 1.
  • The smallest number of cows has a stem of 1 and a leaf of 1. Write the stem first, then the leaf: 11.
  • The smallest number of cows is 11 cows.

Let’s practice!🖊️