O Level E Maths Tuition Singapore/Tuition O Level E Maths/Tutor
Factors and Multiples
1. Multiples
Multiples of a number can be divided exactly by that number with no reminder.
Example:
Multiples of 3: 3,6,9,12,15……..
Multiples of 8: 8,16,24,32……..
2. Factors
Factors of a number are whole numbers that divide into the number exactly.
Example: Factors of 12 are 1,2,3,4,6,and 12
3. Common Factors
The common factors of two numbers are the factors that the numbers have in common.
Example:
Factors of 12: 1,2,3,4,6,12
Factors of 15: 1,3,5,15
Therefore common factors of 12 and 15 are 1 and 3
4. Prime Factorisation
The process of expressing a composite number as the product of prime factors is called prime factorisation.
Example
30 = 2x3x5
2,3, and 5 are the prime factors of 30
5. Highest Common Factor (H.C.F.)
The largest of the common factors is called the highest common factor.
6. Lowest Common Factor (L.C.M)
The smallest of the common multiples is called the lowest common multiple
Example
18 = 2x3x3 = 2×3^2
60 = 2x2x3x5 = 2^2x3x5
H.C.F. = 2×3 = 6
L.C.M. = 2^2 x 3^2 x 5 = 180
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