Is 495.5 Equal to 495? A Mathematical Proof

[zeromodz]

Sorry, I typed the wrong thing in the title, I meant 495.5 = 495

(1/3) + (1/3) + (1/3) = 1
(0.333333333333) + (0.33333333333) + (0.33333333333) = 1
0.999999999999999 = 1
99.9999999 = 100 (Multiplied by 10)
99.1 = 99 (Subtracted 0.9)
495.5= 495 (Multiplied by 5) <---------------PROOF

 

[pbandjay]

Operations on infinite decimal representations need to be considered more carefully.

 

[Office_Shredder]

99.9999999 = 100 (Multiplied by 10)
99.1 = 99 (Subtracted 0.9)

This is not how subtraction is done

100-.9=99?

99.9999999... -.9=99.1?

Both wrong. Even if we assume that you flipped the equation so 100-.9=99.1, 99.99999-.9 is not 99

 

[Werg22]

This is not how subtraction is done

100-.9=99?

99.9999999... -.9=99.1?

Both wrong. Even if we assume that you flipped the equation so 100-.9=99.1, 99.99999-.9 is not 99

The second one is right.

 

[Mentallic]

This is not how subtraction is done

100-.9=99?

99.9999999... -.9=99.1?

Both wrong. Even if we assume that you flipped the equation so 100-.9=99.1, 99.99999-.9 is not 99

The second one is right.

Umm... both 100-.9=99 and 99.999...-.9=99.1 are wrong. So I don't know what you're on about, plus it would've been a lot easier for the reader to determine which "second one" you're talking about by quoting just the relevant equality, not the entire post.

 

[disregardthat]

Umm... both 100-.9=99 and 99.999...-.9=99.1 are wrong. So I don't know what you're on about, plus it would've been a lot easier for the reader to determine which "second one" you're talking about by quoting just the relevant equality, not the entire post.

No, 99.9999...-0.9 = 99.0999... = 99.1 is correct.

 

[uart]

Umm... both 100-.9=99 and 99.999...-.9=99.1 are wrong. So I don't know what you're on about, plus it would've been a lot easier for the reader to determine which "second one" you're talking about by quoting just the relevant equality, not the entire post.

There was nothing wrong with what Werg said. Yes $(99.9999... - 0.9)$ really is equal to 99.1.

I can't believe this senseless OP is going to come back to yet another $0.9999... \neq 1$ debate.

 

[Mentallic]

Oh yes of course, I didn't even stop to think about it once I saw all the recurring decimal places were cut off.