A picture graph shows favorite fruits. The key says: each fruit picture = 2 students. The 'banana' row has 4 pictures. How many students chose banana?
A4 students — you count the pictures
B6 students — you add the pictures to the key number
C8 students — each picture represents 2, so 4 × 2 = 8
D2 students — you divide the pictures by the key number
The key tells you what each picture is worth. If each picture = 2 students, then 4 pictures = 4 × 2 = 8 students. Simply counting the pictures (getting 4) ignores the key and gives the wrong answer. Always check the key first — it defines the value of each symbol, which may or may not be 1.
Question 2 Multiple Choice
A picture graph shows: Dogs row = 3 pictures, Cats row = 5 pictures. The key says each picture = 3 animals. Which category has more, and by how much?
ACats have more — by 2 animals
BCats have more — by 6 animals
CDogs have more — by 2 animals
DCats have more — by 5 animals
Apply the key first: Dogs = 3 pictures × 3 = 9 animals. Cats = 5 pictures × 3 = 15 animals. Cats have more. The difference is 15 − 9 = 6 animals. A student who ignores the key and just compares counts (5 vs 3) gets the right winner but the wrong difference (2 instead of 6). The key must be applied before any comparison or arithmetic.
Question 3 True / False
You cannot correctly read a picture graph without first checking what each picture symbol represents in the key.
TTrue
FFalse
Answer: True
The key is essential — it's the definition of the graph's language. Without it, you don't know if each picture stands for 1 item, 2 items, 5 items, or 10 items. A graph with a key of 'each symbol = 5' looks identical to one with 'each symbol = 1' but produces completely different data. Reading the key is always the first step.
Question 4 True / False
To read a picture graph, you simply count most of the pictures in each row to find the totals.
TTrue
FFalse
Answer: False
Counting pictures only gives the right answer when the key says each picture = 1. If the key says each picture = 2, 5, or 10, you must multiply the count by the key value. Simply counting pictures ignores the key and produces a smaller, incorrect number. The correct process is: check key → count pictures → multiply by key value.
Question 5 Short Answer
What is a picture graph's key, and why must you look at it before counting anything?
Think about your answer, then reveal below.
Model answer: The key tells you how many real items each picture symbol represents. You must check it first because each picture might stand for 1 item, 2 items, or more. If you count pictures without knowing the key's value, you'll get the count of symbols — not the actual data amount. The key is what turns picture counts into real information.
Without the key, a picture graph is unreadable. A row of 3 cat pictures means 3 cats if the key says 1 = 1, but 15 cats if the key says 1 = 5. The key is not optional — it's as fundamental to reading the graph as the scale is to reading a bar graph.