4.5.1 Number Systems

Question 1

Define Natural Numbers.

Answer 1

The set of positive integers and 0. They can be used as cardinal or ordinal numbers.
Symbol N

Question 2

Define Integers.

Answer 2

The set of numbers with no fractional part. The natural numbers are a subset of the integers.
Symbol Z

Question 3

Define Rational Numbers.

Answer 3

The set of numbers that can be expressed as the ratio of two integers. The integers are a subset of the rational numbers since all integers can be expressed as a ratio with 1.
Symbol Q

Question 4

Define Irrational Numbers.

Answer 4

Numbers which cannot be expressed as a ratio of two integers, and hence do not lie within the set of rational numbers.

Question 5

Define Real Numbers.

Answer 5

The set of numbers that can represent real world quantities and have an imaginary part of 0. Rational and Irrational numbers are all members of the real numbers.
Symbol R

Question 6

Define Ordinal Numbers.

Answer 6

Natural numbers used to describe numerical position or order of objects.