.9 Repeating
 

I have heard people debating this all over the net... I want to know what you all think:

Does .9 repeating = 1 ?

Someone please explain!

Re: .9 Repeating
 

.9 repitent doesnt equal 1, for all practical purposes in real life, it does. Mathematically it doesnt. also in real life since nothing is 100% efficient we have tolerances, so it wouldnt matter

Re: .9 Repeating
 

I think .9 repeated does equal 1 because 1/3 = .3 repeated and 1/3 x 3 = 3/3 = 1
.3 repeated x 3 = .9 repeated. Get it?

Here's another way:
let n = .9 repeated
10n = 9.9 repeated
10n - n = 9n 9.9 repeated - n = 9.0
Therefore 9n = 9
9n / 9 = n 9 / 9 = 1
n = 1I think .9 repeated does equal 1 because 1/3 = .3 repeated and 1/3 x 3 = 3/3 = 1
.3 repeated x 3 = .9 repeated. Get it?

Here's another way:
let n = .9 repeated
10n = 9.9 repeated
10n - n = 9n 9.9 repeated - n = 9.0
Therefore 9n = 9
9n / 9 = n 9 / 9 = 1
n = 1

Re: .9 Repeating
 

see here is wehre your wrong keefe, .33333333 repitent * 3 equals .9 repitent on your calc, but nto in real life. cuz you can never get the true value of .9 repitent since it goes on forever, unless it is a fraction. 1/3 is teh true value of .3 repitent.  if you take the true value of teh decimals you will get one, but if you take the approximations on your calc and multiply by 3, you will get and approximation answer, i.e. .9

Re: .9 Repeating
 

1/3 = .3 repeating, so 1/3 * 3 = 1

Re: .9 Repeating
 

and thats it.....???
.any number repeating doesnt have a definate value, therfore you cannot multiply it.  you cannot calculate an infinite number, and that is what you are doing keefe.

Re: .9 Repeating
 

Yes you can.  Have you even taken a math course involving limits?

Re: .9 Repeating
 

EnigmaticPhoenix...can you explan who is right and who is wrong here?

Thanks!

Re: .9 Repeating
 

Just try to tell a bank that the 99 cents in your account is a dollar.  .99999 as far as you want to type it is not 1, only 1 = 1.  There can be only one.  

Re: .9 Repeating
 

I agree with Savage, .9 is .1 from 1, whether it be .1, .01, .001 etc.  Some numbers are simply rounded off. When I budgeted multi-million dollar projects, the 4th or 6th decimal point was used. In large funds, the 4th decimal point will add up to considerable amounts. But .9 is .1 less than 1. Simple as that.