B Taylor 2004 Natural Numbers Integers The counting

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

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

Prime Factor A factor of a number which is also a prime number is called a 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 ÷ 2 6 ÷ 2 3 ÷ 2 1 ÷ 3 Keep dividing by prime numbers until you get to an answer of 1 24 = 2 x 2 x 3 3 = 2 x 3

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.

$Writing a terminating decimal as a fraction (1) Write all the digits after the$

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 0 s (5) Simplify if possible Examples 37 0. 37 = 1 00 213 0. 213 = 1 000 013 0. 013 = 1 000 13 = 1000