Page 1
HCF & LCM
MATHS
Page 2
HCF & LCM
MATHS
Prime Numbers: Building
Blocks
Prime numbers are divisible only by 1 and
themselves.
Example- 2, 3, 5, 7, 11, 13, ...
NOTE - 1 is not prime, 2 is the
only even prime.
Page 3
HCF & LCM
MATHS
Prime Numbers: Building
Blocks
Prime numbers are divisible only by 1 and
themselves.
Example- 2, 3, 5, 7, 11, 13, ...
NOTE - 1 is not prime, 2 is the
only even prime.
COMPOSITE NUMBERS
Composite
numbers have
factors other than
1 and themselves.
EXAMPLES
4, 6, 8, 9, 10,
12, 14, 15, ...
Page 4
HCF & LCM
MATHS
Prime Numbers: Building
Blocks
Prime numbers are divisible only by 1 and
themselves.
Example- 2, 3, 5, 7, 11, 13, ...
NOTE - 1 is not prime, 2 is the
only even prime.
COMPOSITE NUMBERS
Composite
numbers have
factors other than
1 and themselves.
EXAMPLES
4, 6, 8, 9, 10,
12, 14, 15, ...
Twin Primes Prime Triplet
Prime numbers
differing by 2, e.g., (3,
5), (5, 7).
Three prime
numbers differing by
2, e.g., (3, 5, 7).
Co-prime Numbers
Numbers with no
common factor
other than 1, e.g.,
(2, 3), (3, 4).
Page 5
HCF & LCM
MATHS
Prime Numbers: Building
Blocks
Prime numbers are divisible only by 1 and
themselves.
Example- 2, 3, 5, 7, 11, 13, ...
NOTE - 1 is not prime, 2 is the
only even prime.
COMPOSITE NUMBERS
Composite
numbers have
factors other than
1 and themselves.
EXAMPLES
4, 6, 8, 9, 10,
12, 14, 15, ...
Twin Primes Prime Triplet
Prime numbers
differing by 2, e.g., (3,
5), (5, 7).
Three prime
numbers differing by
2, e.g., (3, 5, 7).
Co-prime Numbers
Numbers with no
common factor
other than 1, e.g.,
(2, 3), (3, 4).
_
Divisible by 2
Ends in 0, 2, 4, 6, or
8.
Example- 62, 66,
78,90....
Divisible by 3
Sum of digits is
divisible by 3.
_
Example- 27,30,33,
sum of their digits, is
divisible by 3 (2+7=9,
3+0=3, 3+3=6)
Divisible by 4
Last two digits are
divisible by 4.
_
Example- 112, 196 as
12 and 96 are
divisible by 4
Divisible
by 5
Ends in 0 or 5.
_
Example-
1050,580,695,etc
they end with 0 or 5
DIVISIBILITY RULES
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