Pictograms
A pictogram uses symbols to represent data. A key tells you what each symbol is worth; half-symbols show values in between.
A pictogram (or pictograph) uses repeated pictures or symbols to display data. Each row represents a category, and the number of symbols shows the frequency.
Every pictogram must have a key that states what one symbol represents — for example, "each circle = 4 people". If a value is not a whole multiple of the key, you use a fraction of the symbol. For instance, half a circle = 2 people.
To read a pictogram, count the full symbols, add the value of any partial symbol, and multiply by the key value.
Watch it work
Question: A pictogram shows favourite pets. The key says each symbol = 4. Cat has 3 full symbols and a half-symbol. How many pupils chose cat?
Step 1: Count the full symbols: 3. Value = .
Step 2: Add the half-symbol: half of 4 is 2.
Step 3: Total = pupils.
Have a go
Q1. Each symbol = 5. A row shows 4 symbols. What is the frequency?
Q2. Each symbol = 10. How would you show a frequency of 25?
2 full symbols and a half-symbol: .
Q3. A pictogram shows Walk: 6 symbols, Car: 3 symbols, Bus: 4 symbols. Each symbol = 2. How many more people walk than take the car?
Walk = . Car = .
more people.
Q4. Why does every pictogram need a key?
Without a key, the reader does not know how many items each symbol represents, so the pictogram cannot be read accurately.