Basic Definitions Relating to Numbers
- A Number is a quantity.
- A Numeral is a symbol that represents a number.
- Natural Numbers are the normal whole numbers used for counting and ordering.
- A Cardinal Number is a natural number used for counting (e.g. 1, 2, 3 ...).
- An Ordinal Number is a natural number used for ordering (e.g. 1st, 2nd, 3rd, ...).
- A Whole Number is a number that is not a fractional number.
- Positive Integers are the counting numbers or natural numbers (i.e. 1, 2, 3, ...).
- Negative Integers are the whole numbers less than zero (i.e. -1, -2, -3, ...).
- Non-negative Integers are the positive integers and zero (i.e. 0, 1, 2, 3, ...).
- Integers are the positive and negative whole numbers (i.e. ..., -3, -2, -1, 0, 1, 2, 3, ...).
- Rational Numbers can be written as a ratio of one number to another.
- Integers are rational numbers with a denominator of 1.
- Fractions are rational numbers that are written with a numerator and a denominator.
- Irrational Numbers cannot be written as a ratio (e.g. pi and the square root of 2).
- Real Numbers include all the rational and irrational numbers and can be positive, negative or zero.