POP

G1.13 Reading and Drawing Pictograms

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01 — Explanation

What's the first thing I must check before reading any pictogram?

Always find the key first — it tells you what one symbol is worth. Without it, the symbols are meaningless; a pictogram with a key of "🍕 = 10 pizzas" gives completely different numbers to one with "🍕 = 2 pizzas," even if the picture looks identical.

02 — Explanation

How do I read values off a pictogram once I know the key?

Count the symbols for a category, then multiply by the value of the key.

Example: A key of ❤️ = 2 students. Red has 3 hearts: $3\times2=6$ students. Blue has 4 hearts: $4\times2=8$ students. Green has 2 hearts: $2\times2=4$ students.

From this you can answer follow-up questions directly: the most popular colour is whichever has the most symbols (Blue, with 8); the total surveyed is the sum of every category ( $6+8+4=18$ ); and a comparison like "how many more chose Blue than Red" is just a subtraction ( $8-6=2$ ).

Common Mistake

Forgetting to multiply by the key value and just counting symbols as if each one equals 1 — a pictogram with a key of 2 will give you exactly half the correct answer if you skip this step.

03 — Explanation

How do I represent a value that isn't an exact multiple of the key?

Draw a partial symbol (e.g. half a symbol) sized proportionally to the value it represents. If the key is "🔵 = 2 pets" and a category has 5 pets, $5\div2=2.5$ , so draw 2 full symbols and one half-symbol (representing the remaining 1 pet).

Exam Tip

A half-symbol always represents half the key's value, not "half of whatever's left" — with a key of 10, a half-symbol is always 5, regardless of which category it's attached to.

04 — Explanation

How do I choose a sensible key when drawing my own pictogram?

Look at the data values first. Pick a key that divides into most of the values without leaving awkward fractions, and that doesn't require drawing an excessive number of symbols. A key of 1 is always exact but can mean drawing dozens of symbols; too large a key makes small categories impossible to show clearly.

Example: Data: Dogs 10, Cats 8, Fish 5, Hamsters 2. A key of "🔵 = 2 pets" works well: Dogs need 5 symbols, Cats need 4, Fish need $5\div2=2.5$ (2 full + 1 half), Hamsters need 1.

05 — Worked example

Worked Exam-Style Question

A pictogram shows pizzas sold over a weekend using a key of 🍕 = 10 pizzas: Friday has 2 symbols, Saturday has 4 symbols, Sunday has 3 symbols. (a) How many pizzas were sold in total? (b) The cafe actually sold 25 pizzas on Thursday — how should this be drawn?

(a) Convert each day: Friday $=2\times10=20$ , Saturday $=4\times10=40$ , Sunday $=3\times10=30$ . Total $=20+40+30=90$ pizzas.
(b) $25 \div 10 = 2.5$ , so Thursday should be drawn as 2 full pizza symbols plus one half-symbol (representing the remaining 5 pizzas).

Exam Tip

Always add up the converted values (after multiplying by the key), not the raw symbol counts — adding $2+4+3=9$ and forgetting to multiply by 10 is a very common lost mark on "find the total" pictogram questions.