Multiples/Factors and Prime Numbers

If a number is a multiple of another number, it means that it can be made out of adding groups of the other number together.

• 12 is a multiple of 4 because 4 + 4 + 4 = 12 (or 4 x 3 = 12)

A factor is a number that divides into another number with no remainder.

• A factor is a number that divides into another number with no remainder. In other words every number is divisible by each of its factors.

Multiples and Factors are connected with each other:

if we know that 3 is a factor of 12, then 12 is a multiple of 3

if we know that 33 is a multiple of 11, then 11 is a factor of 33.

also,

if we know that 24 is not a multiple of 7, then 7 is not factor of 24.

Multiple Choice

What are three multiples of 452?

• 452, 904 and 1365

• 452, 904 and 1356

• 452, 940 and 1356

• None of these

Multiple Choice

What are the first two multiples of 32?

• 16 and 32

• 32 and 64

• 8 and 16

• 64 and 96

Prime numbers

• Prime numbers are numbers that have only 2 factors: 1 and themselves.

• For example, the first 5 prime numbers are 2, 3, 5, 7, and 11. 

Multiple Choice

Which of these numbers is prime?

3, 15, 30, 63, 77

• 15

• 3

• 30

• 77

• 63

Multiple Choice

Which of these numbers is prime?

25, 26, 35, 39, 43

• 35

• 39

• 25

• 43

• 26

Multiple Choice

Which of these numbers is prime?

15, 45, 63, 73, 88

• 15

• 88

• 73

• 63

• 45

Composite Numbers

• composite numbers can be defined as the whole numbers that have more than two factors. 

• For example, 4, 6, 8, 9 and 10 are the first few composite numbers.

  
  

• Fun Facts

  1 is neither a prime number nor a compostie number.

• All even number except 2 are composite numbers.

• 4 is the smallest composite number.

Multiple Choice

1 is a prime number.

• True

• False

Multiple Choice

_____ number is neither prime nor composite number.

• 2

• 0

• 1

• None of these

Multiple Choice

Every prime number is odd except _____.

• 0

• 1

• 2

• None of these

The least common multiple

• A common multiple is a multiple that is shared by two or more numbers. 

• 12 is a common multiple of 6 and 4 as it’s in both the 6 and 4 times tables. 

• Three common multiples of 6 and 9 are 18, 36 and 54.

Multiple Choice

Find the LCM of 45 and 60?

• 180

• 160

• 150

• None of these

The highest common factor

• The highest common factor of two numbers is the largest whole number which is a factor of both.

Multiple Choice

What is the HCF of 128, 256 and 512?

• 128

• 64

• 256

• 512

Multiple Choice

Find the smallest number which when divided by 4, 8, 12 and 20 leaves no remainder?

• 210

• 120

• 60

• 45

Multiple Choice

Find the LCM of 150, 300, 600 and 900.

• 300

• 600

• 900

• 1800