Math Core

Imagine 40 kids vote for their favorite lunch. Drawing 40 little pictures would take a long time, and the graph would be huge! A scaled picture graph fixes that. Each picture stands for more than one thing, so the graph stays short and easy to read.

The key tells you the scale

In earlier grades, each picture stood for 1. In a scaled picture graph, every picture stands for the same bigger number, like 2, 5 or 10. A small box called the key tells you that number.

Definition

Key

The key of a picture graph tells how much one picture stands for. For example, the key 🍎 = 2 means every apple picture stands for 2 votes.

You can't read the graph until you read the key. Always look for it first.

Reading a scaled picture graph

To find how many a row shows, skip count by the key number, once for each picture. Or multiply:

\text{number of pictures} \times \text{key number}

How to read a scaled picture graph

Read the key. Find what one picture stands for.
Count the pictures in the row.
Skip count (or multiply) by the key number.

Worked example: Favorite fruit

Room 12 voted for a favorite fruit. Key: 🍎 = 2 votes

Fruit	Votes
Apple	🍎🍎🍎🍎
Banana	🍎🍎🍎🍎🍎🍎
Grape	🍎🍎🍎

How many kids voted for each fruit?

Apple: 4 pictures. Count by 2s: 2, 4, 6, 8. That is 8 votes.
Banana: 6 pictures. $6 \times 2 = 12$ . That is 12 votes.
Grape: 3 pictures. $3 \times 2 = 6$ . That is 6 votes.

Common mistake

The most common mistake is counting pictures and stopping there. The apple row has 4 pictures, but it does not show 4 votes. Each picture is worth 2, so it shows 8. Always use the key!

Comparing rows

Graphs help you answer "how many more?" and "how many in all?" questions. First find the number for each row. Then add or subtract.

Worked example: Books read

A class kept track of the books they read. Key: ⭐ = 5 books

Day	Books read
Monday	⭐⭐⭐
Tuesday	⭐⭐⭐⭐⭐
Wednesday	⭐⭐
Thursday	⭐⭐⭐⭐

How many more books were read on Tuesday than on Wednesday?

Tuesday has 5 stars: $5 \times 5 = 25$ books. Wednesday has 2 stars: $2 \times 5 = 10$ books.

25 - 10 = 15

The class read 15 more books on Tuesday.

Shortcut: Tuesday has 3 more stars than Wednesday. Each star is 5 books, so that is $3 \times 5 = 15$ more books. Same answer!

Half pictures

Sometimes a row needs a number that is between two skip-count numbers. Then the graph uses half of a picture. Half a picture stands for half of the key number.

Worked example: Fish in the pond

Kids counted fish in three ponds. Key: 🐟 = 10 fish, and ½🐟 = 5 fish

Pond	Fish
North	🐟🐟🐟 ½🐟
South	🐟🐟
East	🐟🐟🐟🐟

How many fish are in the North pond?

The 3 whole fish are 10, 20, 30. The half fish adds 5 more: $30 + 5 = 35$ . There are 35 fish in the North pond.

Making a scaled picture graph

To make a graph, pick a key. Then divide each number by the key number to find how many pictures to draw.

Worked example: Pets in third grade

The third graders listed their pets: 12 dogs, 8 cats, 4 birds and 6 fish. Make a picture graph with the key 🐾 = 2 pets.

Find how many pictures each row needs:

Dogs: $12 \div 2 = 6$ pictures
Cats: $8 \div 2 = 4$ pictures
Birds: $4 \div 2 = 2$ pictures
Fish: $6 \div 2 = 3$ pictures

Pet	Number of pets
Dog	🐾🐾🐾🐾🐾🐾
Cat	🐾🐾🐾🐾
Bird	🐾🐾
Fish	🐾🐾🐾

Check one row: 6 paws $\times$ 2 = 12 dogs. ✓

Tip

Pick a key that every number can be split into evenly. For 12, 8, 4 and 6, the key 2 works because each one is a 2s fact. A key of 5 would not work, because 12 is not a 5s fact.

Practice

Practice 1

This graph shows the kids who play soccer. Key: ⚽ = 3 kids

Sport	Kids
Soccer	⚽⚽⚽⚽

How many kids play soccer?

Type a number.

Practice 2

A bake sale graph shows cookies sold on Monday. Key: 🍪 = 5 cookies

Day	Cookies sold
Monday	🍪🍪🍪🍪🍪🍪

How many cookies were sold on Monday?

Type a number.

Practice 3

Mr. Diaz is making a picture graph. Key: 🚗 = 10 cars. He counted 60 cars in the parking lot. How many 🚗 pictures should he draw?

Type a number.

Practice 4

Three friends grew sunflowers. Key: 🌻 = 4 flowers

Friend	Sunflowers
Rosa	🌻🌻🌻🌻🌻
Ali	🌻🌻🌻
Kim	🌻🌻🌻🌻🌻🌻🌻

How many more sunflowers did Kim grow than Ali?

Type a number.

Practice 5

Kids counted balloons at a party. Key: 🎈 = 4 balloons, and ½🎈 = 2 balloons

Color	Balloons
Red	🎈🎈🎈 ½🎈

How many red balloons are there?

Type a number.

Practice 6

Kids counted ladybugs in three gardens. Key: 🐞 = 2 ladybugs

Garden	Ladybugs
A	🐞🐞🐞🐞
B	🐞🐞🐞🐞🐞🐞🐞
C	🐞🐞🐞🐞🐞

How many ladybugs did they count in all?

Type a number.

Practice 7

Jada wants to make a picture graph of this data with no half pictures:

Snack	Votes
Popcorn	15
Pretzels	25
Fruit	10
Yogurt	30

Which key should she use?