Understanding Prime Numbers

What is a prime number?

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

• A prime number is any even number.

• A prime number is a number that can be divided by any other number.

• A prime number is a natural number that is less than 1.

List the first five prime numbers.

• 1, 4, 6, 8, 9

• [2, 3, 5, 7, 11]

• 3, 5, 7, 9, 12

• 2, 4, 6, 8, 10

Is 1 a prime number? Why or why not?

• 1 is a prime number as it has two distinct positive divisors.

• No, 1 is not a prime number.

• Yes, 1 is a prime number because it is only divisible by itself.

• 1 is considered a prime number in some mathematical contexts.

What is the smallest prime number?

• 2

• 1

• 4

• 3

How many prime numbers are there between 1 and 20?

• 12

• 10

• 6

• 8

Is 15 a prime number? Explain your answer.

• No

• 15 is an even number

• Yes

• 15 is a composite number but also prime

What is the largest prime number less than 30?

• 23

• 17

• 19

• 29

Identify if 29 is a prime number and justify your answer.

• Yes, 29 is a prime number.

• 29 is an even number.

• 29 is divisible by 3.

• 29 is a composite number.

What is the difference between a prime number and a composite number?

• Prime numbers have more than two distinct positive divisors; composite numbers have exactly two.

• Prime numbers can be divided by any number; composite numbers cannot.

• Prime numbers are always even; composite numbers are always odd.

• Prime numbers have exactly two distinct positive divisors; composite numbers have more than two.

Can a prime number be even? If yes, give an example.

• Even numbers cannot be prime.

• All prime numbers are odd.

• The only even prime number is 4.

• Yes, an example of an even prime number is 2.