Class VI: Prime Time
Explore prime numbers, composite numbers, divisibility tests and prime factorisation through games, challenges and printable worksheets.
Student Progress
Badge: Explorer
Prime Numbers
A prime number has exactly two factors: 1 and itself.
Examples: 2, 3, 5, 7, 11, 13, 17, 19
Composite Numbers
A composite number has more than two factors.
Examples: 4, 6, 8, 9, 10, 12, 15, 21
Remember
1 is neither prime nor composite. It has only one factor: 1.
2 is the smallest prime number and the only even prime number.
Divisible by 2
Last digit is 0, 2, 4, 6 or 8.
Divisible by 5
Last digit is 0 or 5.
Divisible by 10
Last digit is 0.
Prime Factorisation Rule
Every composite number can be written as a product of prime numbers.
Example: 24 = 2 × 2 × 2 × 3
Practice Lab
Step-by-Step Guidance:
Factor Machine
Enter a number and see its prime factors.
Prime or Composite?
Classify the number.
Divisibility Challenge
Prime Number Sieve
Click “Reveal Primes” to highlight prime numbers from 1 to 50.
Worksheet Generator
Create a printable worksheet for prime and composite numbers.
Internet Security
Prime numbers are used in encryption, which helps protect online payments, passwords and messages.
Everyday Grouping
Factors help us arrange objects equally, form teams, pack items and understand repeated multiplication.
Exit Ticket
Before leaving, answer this: Why is 1 not a prime number?