What a Pictograph Shows
A Chart Made of Pictures
A pictograph uses little pictures to show how many. Our class voted for a favorite fruit, and each picture stands for one child's vote.
Here is what the chart says:
- Apple: 5 pictures, so 5 children.
- Banana: 3 pictures, so 3 children.
- Grape: 6 pictures, so 6 children.
- Orange: 2 pictures, so 2 children.
To read a pictograph, count the pictures in a row. The longest row wins the most votes. The shortest row wins the fewest.
Which Fruit Won?
Your Turn
Look back at the fruit chart. Grape has 6 pictures, apple has 5, banana has 3, and orange has 2.
Numbers You Can See
Why We Make Charts
A chart is a way to see numbers. Instead of reading a list like "5, 3, 6, 2," we can look at rows of pictures and tell at a glance which one is biggest.
When a row is longer or a bar is taller, that means more. When a row is shorter, that means less. Your eyes do the counting for you.
Imagine a bar chart of pets in a class:
- Dogs: a tall bar.
- Cats: a bar a little shorter than dogs.
- Fish: a very short bar.
Even without numbers, you can SEE that dogs are the most and fish are the fewest, just by looking at how tall the bars are.
Tall Means More
Your Turn
In our pet bar chart, the dog bar is tall, the cat bar is a bit shorter, and the fish bar is very short.
A Fair Race
Same Start, Same Size
For a chart to be fair, two things must be true.
One: every bar starts on the same line. Think of a running race. If one runner starts halfway down the track, it is not a fair race. Bars must all start from the same bottom line so we can compare their heights fairly.
Two: on a pictograph, each picture must stand for the same amount. If one apple picture means 1 child but one grape picture means 5 children, counting the pictures would fool you. When every picture equals the same amount, the rows compare fairly.
When bars start on the same line and every picture counts the same, the longest row really is the most. That is a fair chart.
Is It Fair?
Your Turn
Maya makes a pictograph. In the apple row, each apple picture means 1 child. But in the grape row, she says each grape picture means 5 children.
Watch Out for Tricks
When a Picture Fools You
A chart can trick you if the pictures are different sizes. Our eyes judge how much space a picture takes up, so a big picture feels like "more" even when it is only one vote.
Imagine a fruit chart where:
- The apple picture is drawn huge, taking up lots of space, but it means only 3 votes.
- The grape picture is drawn tiny, but it means 6 votes.
At a glance, the giant apple looks like the winner. But if you count the real votes, grape has more! The big picture tricked your eyes.
The lesson: do not just look at how BIG a picture is. Check the real numbers, and make sure each picture is the same size and counts the same amount.
Spot the Trick
Your Turn
A chart draws a giant apple picture that means 3 votes and a tiny grape picture that means 6 votes. The apple looks bigger, so it seems like apple won.