Number Systems

Question 1

What are natural numbers?

Answer 1

ℕ is the set of natural numbers used for counting

ℕ = {0,1,2,3,4, … }

Question 2

What are Integer Numbers?

Answer 2

• whole numbers
• ℤ is the set of integer numbers, which include the natural numbers and their negative inverses

ℤ = {… -2, -1, 0, 1, 2 … }

Question 3

What are Rational Numbers?

Answer 3

ℚ is the set of numbers that can be written as simple fractions

Question 4

What are irrational numbers?

Answer 4

An irrational number cannot be written as a ratio of two numbers.

Question 5

What are real numbers?

Answer 5

ℝ is the set of real numbers, which includes: whole numbers, integers, rational and irrational numbers; they can be positive, negative or zero.

• R includes:1,12.41,√2, 0, 12/7, 1/8, 1.23423, 129.6

Question 6

What are ordinal numbers?

Answer 6

Ordinal numbers are used to describe the position of an object in an ordered list.