Grade 4 | Maths | Multiples, Factors and Multiples, Olympiad, CBSE, ICSE, Maths Olympiad, Science Olympiad, English Olympiad
Multiples
The numbers we get by multiplying a given number are called multiples of the given number. These are essentially the numbers found in multiplication table of the number.
The smallest multiple of a number is the number itself. Biggest multiple of a number is very big and can't be determined. Multiples of a number are unlimited.
*Factors of a number are limited and biggest factor of a number is the number itself.
E.g.
Multiples of 6 are 6 X 1, 6 X 2, 6 X 3, 6 X 4 , 6 X 5, 6 X 6 etc.
or we can say 6, 12, 18, 24, 30, 36 etc. are multiples of six.
Common multiples: The multiples which are common between 2 numbers are called multiples. Common multiples of two numbers are infinite.
L.C.M. or lowest common multiple: The lowest number between the common multiples of two numbers is called the L.C.M. of two numbers.
E.g.
Multiples of 6 are 6, 12, 18, 24, 30, 36, 42, 48, 54, 60, 66, 72 etc
Multiples of 8 are 8, 16, 24, 32, 40, 48, 56, 64, 72, 80, 88, 96 etc
24, 48 and 72 and so on are common multiples of 6 and 8. 24 is the lowest common multiple so it is the L.C.M. of 6 and 8.
Imp Concept:
Rules of divisibility
If a number is even it is divisible by 2.
A number is divisible by 3 if the sum of the digits of the number is divisible 3. E.g. Is 4635 divisible by 3? 4 + 6 + 3 + 5=18. 18 is divisible by 3 so the number 4635 is divisible by 3.
A number is divisible by 4 if the number formed by its last two digits is divisible by 4. E.g. to check if 47932 is divisible by 4, check if last 2 digits 32 is divisible by 4. Yes, 32 is divisible by 4 so the number 47932 is divisible by 4.
If a number has 0 or 5 as the last digit then the number is divisible by 5.
A number is divisible by 9 if the sum of the digits of the number is divisible by 9. E.g. Is 4635 divisible by 9? 4 + 6 + 3 + 5=18. 18 is divisible by 9 so the number 4635 is divisible by 9.
A number is divisible by 10 if the last digit is 0.
Practice that feels like the real Olympiad.
Achievers’ question banks that mirror the exam. Less theory. More score.
* Olympiad Genius is an independent organization and is not an official partner of SOF (Science Olympiad
Foundation), Silverzone and Indian Talent Olympiad Organizations.