GCSE Secondary Maths Age 13-17 - Number: Prime Numbers - Explained

The video tutorial covers identifying prime numbers between 20 and 30, explaining the concept of prime numbers as having only two factors: 1 and itself. It demonstrates the process of eliminating non-prime numbers by checking divisibility and highlights that 23 and 29 are the only primes in the given range. The tutorial also addresses the uniqueness of 2 as the only even prime number, explaining that all other even numbers have additional factors, making them non-prime.

Explain why 21 is not a prime number.

What makes 23 a prime number?

What are the prime numbers between 20 and 30?

Why is 2 considered the only even prime number?

List all even numbers and explain why they are not prime.