Prime, Composite and Divisibility

Front

What is a prime number?

Back

A prime number is a natural number greater than 1 that has no positive divisors other than 1 and itself.

Front

What is a composite number?

Back

A composite number is a natural number greater than 1 that is not prime, meaning it has at least one positive divisor other than 1 and itself.

Front

Is the number 1 considered prime or composite?

Back

Neither; the number 1 is neither prime nor composite.

Front

What is the definition of divisibility?

Back

A number 'a' is divisible by another number 'b' if there exists an integer 'k' such that a = b * k.

Front

What are the divisibility rules for 2?

Back

A number is divisible by 2 if it is even, meaning its last digit is 0, 2, 4, 6, or 8.

Front

What are the divisibility rules for 3?

Back

A number is divisible by 3 if the sum of its digits is divisible by 3.

Front

What are the divisibility rules for 5?

Back

A number is divisible by 5 if its last digit is 0 or 5.

Front

How can you determine if a number is prime?

Back

To determine if a number is prime, check if it has any divisors other than 1 and itself by testing divisibility with prime numbers up to its square root.

Front

What is the smallest prime number?

Back

The smallest prime number is 2.

Front

What is the largest two-digit prime number?

Back

The largest two-digit prime number is 97.