IGCSE MATHEMATICS
1. Numbers
Number Definition Example
Natural number Any whole number from 1 to ∞ 1, 2, 3, 4, 5….
Integer Any of the negative/positive whole numbers including ... − 3, − 2, − 1, 0, 1, 2....
0
Prime number Whole number > 1 which only has 2 factors (the 2, 3, 5, 7, 11...
number itself & 1)
Square number Product obtained when an integer is multiplied by 1, 4, 9, 16, 25....
itself
es
Cube number Product obtained when an integer is multiplied by 1, 8, 27, 64
itself & then by itself again
ot
Factors All the numbers which will divide exactly into a Factors of 12:
N
number 1, 2, 3, 4, 6, 12
Prime factors Prime numbers which will divide exactly into a number Prime factors of 12:
SE
2, 3
Product of prime numbers The product of all the prime factors
C
3
PPF of 40: 2 × 5
IG
Highest common factors The biggest number that divides exactly into both HCF of 28 & 16 is 4
(HCF) numbers 28: 1, 2, 4, 7, 14, 28
16: 1, 2, 4, 8, 16
ay
Lowest common multiple Smallest number that appears in multiplication tables LCM of 18 & 24 is 72
(LCM) of both numbers 18: 18, 36, 54, 72, 90, 108...
24: 24, 48, 72, 96, 120...
nj
Rational number Any number that can be expressed as a fraction 0. 2 =
1
, 7=
7
Sa
5 1
Irrational number Can’t be expressed as a fraction 2, 6 − 3, π
Real number All possible rational & irrational numbers 0.2, 2
a
ni
Reciprocals 1 divided by the number 5→
1
5
● Sets & Venn Diagram
So
● Limits of accuracy
○ Significant figures
1. Numbers
Number Definition Example
Natural number Any whole number from 1 to ∞ 1, 2, 3, 4, 5….
Integer Any of the negative/positive whole numbers including ... − 3, − 2, − 1, 0, 1, 2....
0
Prime number Whole number > 1 which only has 2 factors (the 2, 3, 5, 7, 11...
number itself & 1)
Square number Product obtained when an integer is multiplied by 1, 4, 9, 16, 25....
itself
es
Cube number Product obtained when an integer is multiplied by 1, 8, 27, 64
itself & then by itself again
ot
Factors All the numbers which will divide exactly into a Factors of 12:
N
number 1, 2, 3, 4, 6, 12
Prime factors Prime numbers which will divide exactly into a number Prime factors of 12:
SE
2, 3
Product of prime numbers The product of all the prime factors
C
3
PPF of 40: 2 × 5
IG
Highest common factors The biggest number that divides exactly into both HCF of 28 & 16 is 4
(HCF) numbers 28: 1, 2, 4, 7, 14, 28
16: 1, 2, 4, 8, 16
ay
Lowest common multiple Smallest number that appears in multiplication tables LCM of 18 & 24 is 72
(LCM) of both numbers 18: 18, 36, 54, 72, 90, 108...
24: 24, 48, 72, 96, 120...
nj
Rational number Any number that can be expressed as a fraction 0. 2 =
1
, 7=
7
Sa
5 1
Irrational number Can’t be expressed as a fraction 2, 6 − 3, π
Real number All possible rational & irrational numbers 0.2, 2
a
ni
Reciprocals 1 divided by the number 5→
1
5
● Sets & Venn Diagram
So
● Limits of accuracy
○ Significant figures
