Factors
Identifying prime numbers by finding their factors is a foundational skill in Grade 6 Saxon Math Course 1. Prime numbers have exactly two factors: 1 and the number itself. Composite numbers have more than two factors. Students test whether a number is prime by checking divisibility by all primes up to its square root. For 97: check divisibility by 2, 3, 5, 7 (primes up to √97 ≈ 9.8) — none divide evenly, so 97 is prime. This prime-identification skill supports all factorization and GCF/LCM work.
Key Concepts
New Concept The factors of a given number are the whole numbers that divide the given number without a remainder. Counting numbers that have exactly two factors are prime numbers . What’s next This is your introduction to these key number properties. Now, we'll apply these definitions with worked examples on listing factors and identifying various prime numbers.
Common Questions
How do you test whether a number is prime?
Check divisibility by all primes up to the square root of the number. If none divide evenly, the number is prime.
Is 97 a prime number?
Check primes up to √97 ≈ 9.8: 2, 3, 5, 7. None divide 97 evenly. Yes, 97 is prime.
List all prime numbers between 1 and 20.
2, 3, 5, 7, 11, 13, 17, 19.
Why is 2 the only even prime number?
Every other even number is divisible by 2, giving it at least three factors: 1, 2, and itself.
What is the difference between prime and composite numbers?
Prime: exactly two factors (1 and itself). Composite: three or more factors. The number 1 is neither.