Classify numbers as prime or composite and justify the classification with factors.
A number is prime when it has exactly two factors. Getting children to justify the answer — naming an actual factor pair for composite numbers — matters more than the label itself, and the questions push for that.
Examples of what the practice generator produces. Answers are shown so parents and teachers can judge the level before starting.
1. Is 17 a prime number or a composite number?
EasyAnswer: Prime
2. Is 21 prime or composite? Give a reason.
MediumAnswer: Composite - it is 3 x 7
3. List all the prime numbers between 10 and 20.
HardAnswer: 11, 13, 17, 19
Questions are generated fresh each time, so they never run out.
Printable worksheets
Generate a prime & composite numbers worksheet of 5–20 questions with a separate teacher answer key, ready to print for a class or for homework.
Three difficulty levels
Easy, Medium and Hard run side by side, so a mixed-ability class can work on the same topic at the level that suits each child.
Instant feedback
Children get up to three attempts with step-by-step working revealed afterwards — no marking needed for practice sessions.
Nothing to set up
No accounts, no logins, no data collected from children. Open the page on any school device and start.
StudyZone is a fun practice tool, not an assessment platform.
Questions are randomly generated and are not a substitute for formal evaluation. A child's performance here does not reflect their academic ability or school readiness.