Introductory Numbers

Natural Numbers - the counting numbers. Examples: 1, 2, 3, 4

Whole Numbers - the natural numbers and zero. Examples: 0, 1, 2, 3, 4

Integers - negative natural numbers, zero, and the positive natural numbers. Examples: –4, –3, –2, –1, 0, 1, 2, 3, 4

Prime Number - a natural number whose only factors are itself and 1. The number 3 is a prime number because its only factors are itself and 1 (3 × 1 = 3). Prime numbers do not include 1. Examples: 2, 3, 5, 7, 11, 13, 17, 19

Composite Number - a natural number that is not prime. Examples: 4, 6, 8, 9, 10, 12, 14, 15, 16, 18, 20

Common Fraction - part of a whole written with a numerator (the number above the vinculum line) and a denominator (the number below the vinculum line). Examples: ¹⁄₂, ¹⁄₁₀, ²⁄₃

Decimal Fraction - parts of a whole expressed where the parts are expressed in tenth parts. Examples: 0.5, 0.79, 0.857

Terminating Decimal Fraction - a decimal fraction which has a definite ending. Examples: 0.5, 0.75, 0.467

Recurring Decimal Fraction - a decimal fraction where one digit or a group of digits repeats. A line over the digits indicates what digits repeat. Examples: ¹⁄₉ = 0.111111..., ¹⁄₃ = 0.33333..., ²⁄₁₁ = 0.18181818...

Index (Plural is indices) - an exponent, a power. Used when a number is multiplied by itself. Examples: 100 = 10 squared = 10 to the index of 2 = 10²

NAME	AMOUNT	NUMERALS
Million	a thousand thousand	1 000 000
Billion	a thousand million	1 000 000 000
Trillion	a thousand billion	1 000 000 000 000
Quadrillion	a thousand trillion	1 000 000 000 000 000
Pentillion	a thousand quadrillion	1 000 000 000 000 000 000

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