February 4th, 2019, 12:40 PM  #1 
Banned Camp Joined: Mar 2015 From: New Jersey Posts: 1,720 Thanks: 125  Counting real numbers
To count the real numbers in [.1,1), remove the decimal point.

February 4th, 2019, 12:53 PM  #2 
Math Team Joined: May 2013 From: The Astral plane Posts: 2,226 Thanks: 908 Math Focus: Wibbly wobbly timeywimey stuff. 
What is [.1,1) after you take away the decimal point? [1, 1) makes no sense! Again with the counting? What exactly are you getting out of this? You know that no one is going to agree with your arguments as they haven't for the last, what, 10 or so threads? Dan 
February 4th, 2019, 12:57 PM  #3 
Global Moderator Joined: Dec 2006 Posts: 20,820 Thanks: 2159 
I tried it, but most of them went away, saying that counting them would be pointless.

February 4th, 2019, 01:16 PM  #4  
Banned Camp Joined: Mar 2015 From: New Jersey Posts: 1,720 Thanks: 125  Quote:
[.1,1) is an interval of real numbers. .1 > 1 .105 > 105 .13 > 13 .333 > 333 Every real number in the INTERVAL [.1,1) maps to a unique natural number. I'm trying to make it as simple as possible.  
February 4th, 2019, 01:24 PM  #5 
Global Moderator Joined: Dec 2006 Posts: 20,820 Thanks: 2159 
That doesn't help you count them.

February 4th, 2019, 02:43 PM  #6 
Senior Member Joined: Aug 2012 Posts: 2,342 Thanks: 731  
February 4th, 2019, 02:50 PM  #7  
Math Team Joined: May 2013 From: The Astral plane Posts: 2,226 Thanks: 908 Math Focus: Wibbly wobbly timeywimey stuff.  Quote:
Dan  
February 4th, 2019, 03:44 PM  #8 
Global Moderator Joined: Dec 2006 Posts: 20,820 Thanks: 2159 
That must be what zylo meant, but removing those decimal points doesn't help one count the numbers or prove that they can be counted.

February 4th, 2019, 04:10 PM  #9 
Math Team Joined: Dec 2013 From: Colombia Posts: 7,671 Thanks: 2651 Math Focus: Mainly analysis and algebra  
February 4th, 2019, 04:48 PM  #10 
Member Joined: Jun 2007 From: Richmond, VA Posts: 46 Thanks: 0 
Your example of four numbers above conveniently does not include any reals with an infinite number of (nonzero trailing) digits. There are such reals, but none maps to any integer.


Tags 
counting, numbers, real 
Search tags for this page 
Click on a term to search for related topics.

Thread Tools  
Display Modes  

Similar Threads  
Thread  Thread Starter  Forum  Replies  Last Post 
Real Numbers and Natural Numbers  zylo  Topology  14  May 10th, 2017 01:57 AM 
Dimensions, and numbers beyond real numbers  Elektron  Math  4  May 7th, 2017 11:47 AM 
The relationship of Counting number field & Prime numbers  SophiaRivera007  Math  4  January 15th, 2017 09:57 PM 
Counting the Irrational Numbers  zylo  Topology  67  March 5th, 2016 09:58 AM 
Relations, attributes, and counting to really big numbers  CRGreathouse  Applied Math  2  April 22nd, 2010 05:30 AM 