3. What are
factors?
A number or
quantity that
when multiplied
with another
produces a given
number or
expression.
A factor is a number that divides another number, leaving no
remainder.
Example :
1 × 5 = 5
The factors of 5 are 1 and 5.
How about 12?
4. 2.1 Factors, Prime Factors and Highest
Common Factor (HCF)
1. List all the factors of a number.
a)18 b)40 c) 98 d) 100 e) 124
f) 240 g) 369 h) 1000
2. Determine whether each of the following number is a prime number factor of 24.
a) 2 b)3 c)11
3. Write each of these numbers as a product of prime numbers using the suitable method.
a) 60 b) 90 c) 110
5. What is Prime
Number?
A prime number
is a natural
number greater
than 1, which is
only divisible by 1
and itself.
7. Common Factors and Highest Common
Factors
Common Factor
A common factor is a factor shared or joint
between two or more numbers
Example:
2 𝑎𝑛𝑑 4
Highest Common Factor
The highest common factor (HCF) is the largest
common of two (or more) whole number.
Example:
2 𝑎𝑛𝑑 4
8. 2.1 Factors, Prime Factors and Highest
Common Factor (HCF)
3. Determine the common factors of
a)20,44 b)35, 90 𝑎𝑛𝑑 150
2. Determine the highest common factors of .
a) 36, 60 and 72 b) 48, 64 and 80
9. 2.1 Factors, Prime Factors and Highest
Common Factor (HCF)
5. Write the prime factorisation of 1968 and 4968. Hence, find the highest common factor of 1968 and
4968.
6. The highest common factor of 𝑛 and 36 is 4. If 𝑛 is less than 36, what are the possible values of 𝑛?
7. Three pieces of sting have a length of 192 cm, 242 cm, and 328 cm respectively. Aina wishes to cut the
strings so that every piece is cut into the same number of segments with no extra string left. What would be
the maximum number of segments that each piece of string can be cut into?
10. 2.2 Multiples, Common Multiples and the
Lowest Common Multiples
Multiple
• The product of a quantity and an integer
Common Multiple
• A number that is multiple of two or more numbers or expressions
Lowest Common Multiple
• The smallest integer that belongs to the multiplication table or two or
more numbers
13. 12, 24 and 36
Example:
What is the first
three common
multiple of 3
and 4
14. 2.2 Multiples,
Common Multiples
and the Lowest
Common Multiples
Listing the common
multiple
Repeated division
Prime factorisation
Method in
finding the
Lowest
Common
Multiple
15. Method in finding
the Lowest
Common Multiple
Determine the lowest common multiple of
a) 2 and 3
1) Listing the
common multiple
16. Try this!
By using the method of listing the common multiple,
find the LCM of 4 and 6.
Ans: 12
17. Method in finding
the Lowest
Common Multiple
Determine the lowest common multiple of
a) 3,6 and 9
2) Repeated
Division
18. Try this!
By using the Repeated Division Method, determine
the LCM of
a) 10 and 15 b) 18 and 60
Ans: 30 180
19. Method in finding
the Lowest
Common Multiple
Determine the lowest common multiple of
a) 3,8 and 12
3)Prime
Factorisation
20. Try this!
By using the Prime Factorisation Method, determine
the LCM of
a) 16 and 18 b) 6, 15 and 18
Ans: 72 90
