Factors and Multiples

Factors and Multiples

Form One

Factors

5 and 7 are the FACTORS of 35

35 is the MULTIPLE of 5

35 is the MULTIPLE of 7

Common Factor of 16 and 24

ANSWER IS 8

Highest Common Factor(HCF) OF 18 AND 24

ANSWER IS 6

Multiple Choice

List the factors of 49.

• 1,3,5,7

• 1,7,49

Multiple Choice

List the factors of 78.

• 1,2,3,6,13,26,39,78

• 1,2,3,7,8

Multiple Choice

List the multiples of 3.

• 3,5,7,9,11,13,...

• 3,6,9,12,15,18,...

Multiple Choice

List the multiples of 7

• 1,7,.....

• 7,14,21,28,35,.....

Open Ended

List the smallest prime number.

Open Ended

Calculate the common prime factor of 21 and 24.

(Factor Tree Method)

Open Ended

Calculate the highest common factor of 18 and 30.

(Repeated Division)

Open Ended

Calculate the lowest common multiple of 12 and 18.

It is given that 5 is a factor of the number P, and P is a factor of 75.

State all the possible values of P.

-->P is the multiple of 5

-->P is a factor of 75

The numbers 84, 108 and 192 are divisible by Q exactly.

What is the greatest possible value of Q?

• 84,108和192可以被Q整除。

• 找Q的最大值。

• 从中，得知道Q就是84，108和192的factor

Calculate the Common Multiple of 9 and 12.

Calculate the first 3 common multiple of 9 and 12

• 用Repeated Division或Prime Factorization找出LCM

• 因为LCM是9和12的第一个共同的倍数（multiple）

• 首五个相同的倍数：1 X LCM，2 X LCM，3 X LCM

• LCM是36； 1X36,2X36,3X26

• First 3 common multiple are 36,72,108

Multiple Choice

List the multiples of 3.

• 3,5,7,9,11,13,...

• 3,6,9,12,15,18,...