Math Is Fun Forum

Maelwys

Member

Registered: 2007-02-02

Posts: 161

Re: INFINITE 0.9 <> 1 PROOF : COMPLETE : By,Anthony.R.Brown,15/02/07

1 is divided by 0.9 = 1.111....." this proves 0.9 is less than 1 "

Okay, I'm with you so far. 0.9 < 1.

i'm now going to mutiply it so nothing will change!

0.9 x 1.111.... " will always equal a Value less than 1 " because 0.9 was divided within a greater Value! that Value being 1

Lost me here. How do you conclude that the answer will be less than 1, based on a previous calculation you did? My logic tells me that it's equal to 1. My calculator tells me that it's equal to 1. It seems to me like it should be equal to 1. Why isn't it?

Anthony.R.Brown

Banned

Registered: 2006-11-16

Posts: 516

Re: INFINITE 0.9 <> 1 PROOF : COMPLETE : By,Anthony.R.Brown,15/02/07

To Maelwys

Quote:

"Lost me here. How do you conclude that the answer will be less than 1, based on a previous calculation you did? My logic tells me that it's equal to 1. My calculator tells me that it's equal to 1. It seems to me like it should be equal to 1. Why isn't it?"

A.R.B

Because we are Calculating an Infinite Number!! and Calculators Round the Number up!!

Lets look at the Start again!

Infinite 0.9 "one Decimal place " x 1.1 = 0.99

Infinite 0.9" two Decimal place's " x 1.11 = 0.999

No matter how many times we Calculate the 1.1 " Decimal place's " " it is always less than 1

The reason being the .1 at the end of the Multiplied Value it starts with!! the Decimal point Value Difference! and because the Number is being Multiplied Infinitely will always be there!
The only way it can disappear! is by using an Algebra sign! or even the INT function

mathsyperson

Moderator

Registered: 2005-06-22

Posts: 4,900

Re: INFINITE 0.9 <> 1 PROOF : COMPLETE : By,Anthony.R.Brown,15/02/07

Looks like this is turning into another duplicate discussion thread.
As such, it's probably time that it was closed. I'll close the sister thread as well, to be fair.

Please continue discussion in the original topic: http://www.mathsisfun.com/forum/viewtopic.php?id=658

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Why did the vector cross the road?
It wanted to be normal.