This document discusses divisibility and related mathematical concepts. It defines divisibility as when the division of one number by another is exact. Multiples are numbers that are exactly divisible by another number, while factors are the numbers that divide into another number. Prime numbers only have two factors, 1 and themselves, while composite numbers have more than two factors. The document also outlines some basic rules of divisibility and defines the highest common factor and lowest common multiple, providing examples of each.

1. UNIT 2 DIVISIBILITY
Manuel Jiménez Martínez 1ºA

2. INDEX
- Divisibility
- Multiples and factors
- Prime number
- Composite number
- Rules of divisibility
- H.C.F.
-L.C.M.

3. WHEN IS A NUMBER DIVISIBLE
BY ANOTHER NUMBER?
When the division is exact.
EXAMPLE: 18 : 2 = 9
Eighteen is divisible by nine and two.

4. When is a number multiple or factor
of another number?
When the division is exact
EXAMPLE: 28 : 4 = 7
Twenty-eight is multiple of four
Four is factor of twenty-eight

5. What are prime numbers?
Are numbers with only two divisors, 1 and itself
EXAMPLE: The prime numbers are 2,3,5,7,11,
13,17,19,23,29,31,37,41,43,47,53,59,61,67,
71,73,79,83,89 and 97.

6. What are composite numbers?
Are numbers with more than two divisors
EXAMPLE: 10 = 1,2,5 and 10

7. RULES OF
DIVISIBILITY

9. H.C.F. AND L.C.M
●
EXAMPLE: ●
EXAMPLE:
●
H.C.F(18 and 9)= ●
L.C.M(10 and 5)=
2·3·3= 18 ●
2·5= 10
●
18=2·3·3 ●
10= 2·5
●
9=3·3 ●
5= 5

10. THE END