Roster Method & Set-Builder Notation...3

College Algebra
Chapter 1/Section 1
Review

We begin our College Algebra journey with a review of the basics according to the author of the textbook.

Working with sets.

There are two methods for denoting sets:

Roster Method
Set-Builder Notation

Let O = set of odd digits

Roster Method

O = {1, 3, 5, 7, 9 }

I never understood 1 as an odd digit.

You say?

Set-Builder Notation

O = { x| x is an odd digit }

You say?

 

I never understood 1 as an odd digit.
Odd numbers are positive integers that cannot be categorized into groups of two. For example: 1, 3, 5, 7, etc.

 

What do you mean that odd numbers cannot be categorized into groups of two?