A picture graph has a key that says 'each star = 2 students.' Row A has 3 stars and Row B has 5 stars. How many more students chose B than A?
A2 more students — because 5 − 3 = 2
B4 more students — because (5 × 2) − (3 × 2) = 10 − 6 = 4
C8 more students — because you add the rows together
D5 more students — because Row B has 5 symbols
You must apply the key before comparing rows. Row A: 3 stars × 2 = 6 students. Row B: 5 stars × 2 = 10 students. 10 − 6 = 4 more students. Option A is the classic mistake: comparing the symbol counts directly without using the key, which only works when each symbol = 1.
Question 2 Multiple Choice
What is the purpose of the key (or legend) on a picture graph?
ATo make the graph look more colorful and interesting
BTo tell the reader what each symbol stands for so they can calculate the correct amounts
CTo show which category got the most votes
DTo label each row with its category name
The key defines what each symbol is worth. Without reading the key first, you cannot correctly interpret any row. If each symbol represents 2 items instead of 1, counting symbols without multiplying will give you an answer that's half the correct value.
Question 3 True / False
When a picture graph's key says each symbol equals 2, a row with 4 symbols represents 8 items.
TTrue
FFalse
Answer: True
4 symbols × 2 items per symbol = 8 items. This is the core calculation skill in picture graphs: multiply the symbol count by the key value to get the actual quantity represented.
Question 4 True / False
A picture graph usually uses exactly one symbol per item counted.
TTrue
FFalse
Answer: False
The key can assign any value to each symbol — commonly 2, 5, or 10 items per symbol. Always check the key before counting. This is why reading the key is the essential first step: it tells you the scale the graph is using.
Question 5 Short Answer
A picture graph shows 'favorite pets.' The key says each paw print = 5 students. The 'dog' row has 4 paw prints. How many students chose dog, and how do you figure it out?
Think about your answer, then reveal below.
Model answer: 20 students. Multiply the number of symbols by the key value: 4 paw prints × 5 students each = 20 students.
The key acts as a conversion factor between symbols and real quantities. You always multiply: (number of symbols) × (key value) = actual count. If the key said 1 paw = 1 student, you would just count — but when each symbol represents more than one, multiplication is required.