Topic 5.1 - Number Systems

Question 1

What is a natural number and the set notation?

Answer 1

A natural number is any positive whole number including 0
ℕ = {0,1,2,3,4,5,6,…}

Question 2

What is an integer and the set notation?

Answer 2

An integer is any whole number, positive and negative
ℤ = {… , -3,-2,-1,0,1,2,3, …}

Question 3

What is a rational number and the set notation?

Answer 3

A rational number is any number that can be written as a fraction
Important to note that all integers are included in the set of rational numbers

ℚ = {… , -3/2 , -1, -1/2, 0, 1/2, 1, 3/2, …}

Question 4

What is an irrational number?

Answer 4

A number which cannot be written as a fraction
E.G. √2

Question 5

What is a Real Number with Set Notation?

Answer 5

ℝ is the set of all possible values
ℝ includes all natural, integer, rational and irrational values

Question 6

What is an Ordinal Number and their use?

Answer 6

An ordinal number is a number that is used to explain the position an object holds in an ORDERED list.
E.G. 1st, 2nd, 3rd etc

Question 7

What number system is used for counting?

Answer 7

Natural numbers are used for counting since they contain all possible positive whole numbers.

Question 8

What number system is used for measurement?

Answer 8

Real numbers are used for measurement since measurements can take up any value and the set of real numbers contain all the values.