1. Types of Number
© B. Taylor

2. N Z Q R Natural Numbers 1, 2, 3, 4, 5, . . . Integers
The counting numbers N
Natural Numbers
1, 2, 3, 4, 5,
Include all the whole numbes and zero Z
Integers
, -2, -1, 0, 1, 2, 3, . . .
Include all the integers plus fractions Q
Rational Numbers
Include all the Rational Numbers plus numbers that cannot be written as fractions R
Real Numbers

3. Factor Prime Number 2, 3, 5, 7, 11, 13, 17, . . . Prime Factor
A factor of a number divides exactly into that number
Factor
eg: Factors of 14 are:
1, 2, 7 and 14
A number with exactly TWO factors: (1 and itself)
Prime Number
2, 3, 5, 7, 11, 13, 17, . . .
A factor of a number which is also a prime number is called a prime factor
Prime Factor

4. A factor of a number which is also a prime number is called a prime factor

5. 24 = 2 x 2 x 2 x 3 = 2 x 3 24 12 6 3 1 ÷ 2 ÷ 2 ÷ 2 ÷ 3 Prime Factor
A factor of a number which is also a prime number is called a prime factor
Prime Factor
eg 1: Write 24 as a product of Prime Factors 24 12 6 3 1
Keep dividing by prime numbers until you get to an answer of 1
÷ 2
÷ 2
÷ 2
÷ 3
24 = 2 x 2 x 2 x 3 3
= x 3

6. REAL NUMBERS Rational Numbers Irrational Numbers
These include all the whole numbers and numbers which can be written as a fraction.
These are all the and numbers which can NOT be written as a fraction.
ALL decimals which recur or terminate can be written as fractions.
Examples: pi
Square roots of primes and multiples of primes.

7. Writing a terminating decimal as a fraction
(1) Write all the digits after the decimal point
(2) Draw a line under these
(3) Put a 0 under each digit
(4) Put a 1 in front of the 0s
(5) Simplify if possible
Examples 37
213
013
0.37
0.213 =
0.013 = = 1 00 1
000 1
000 13 =
1000