To determine if a number is prime or composite, follow these simple steps:
- Definition Check: A prime number is greater than 1 and has no divisors other than 1 and itself. A composite number is also greater than 1 but has additional divisors.
- Start with 2: If the number is 2, it’s prime. If it’s less than 2, it’s neither prime nor composite.
- Test for Divisibility: Check for divisibility starting from 2 up to the square root of the number (rounded up). If the number can be divided evenly (without a remainder) by any of these numbers, it is composite.
- Conclusion: If the number cannot be evenly divided by any numbers other than 1 and itself, it’s prime. If it can, it’s composite.
For example, to determine if 29 is prime, you test divisibility by numbers up to its square root (about 5.39). Since 29 isn’t divisible by 2, 3, or 5, we conclude that 29 is a prime number.