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

The video tutorial explains factors and prime numbers, focusing on the factors of 18. It lists the factors of 18 and defines prime numbers as those with only two factors. The tutorial demonstrates how to find combinations of factors that sum to a prime number, using trial and error. It concludes with scoring criteria for finding such combinations.

What is a factor of a number?

• A number that is less than another number

• A number that is equal to another number

• A number that is greater than another number

• A number that divides another number exactly

Which of the following is NOT a prime number?

• 2

• 4

• 5

• 7

What is the only even prime number?

• 2

• 3

• 4

• 1

Which combination of factors of 18 adds up to a prime number?

• 1, 2, 3

• 2, 6, 9

• 3, 4, 5

• 5, 6, 7

How many marks are awarded for finding three factors of 18 that add up to a prime number?

• One mark

• Two marks

• Three marks

• Four marks