Rounding

It came to my attention not 10 minutes ago that people do not understand rounding. My college-student sister believes that 89.49 rounds up to 90. However, this is incorrect. 89.49 rounds down to 89.


She is stupid, and ran away to cry in her room before I could pull out my proof off the internet, but since I went through all this effort, I decided to share it with you guyses.
According to mathisfun.com you must decide which is the last digit to keep and increase that digit by 1 if the next digit is 5 or more or leave it the same if the next digit is less than 5.

You cant conclude that 89.49 rounds to 89.5 and thus rounds to 90. That is wrong. DEAD WRONG. So if my sister's professor is reading this, She earned a B+, not an A-, change it back.

 

89.50 - 1/infinity is rounded to 89. Duh.

 

"bla bla bla I am right about rounding so ha"

 

Yeah, thats what I said.

 

Your sister is obviously unintelligent.

 

Anybody who doesn't know that is obviously stupid and has no place on this earth.

 

woah i got in an arguement with my teacher about this the other day, i had the same opinion as your sister.

Guess I don't deserve a place on this earth.

*Runs into room and slams the door.*

 

YOU'RE WRONG!!

 

89.4 is 89 if it where 89.5 then it would be 90

I understood that for a long time

 

I thought it was like a domino effect where the 9 makes it go to a 5 then the 5 makes it a 90. And since Im the best that is the way it is going to be from now on.

 

when you round it off to the nearest digit, a 4 isn't close to the next number, its closer to 89, 1 2 3 4 stays the same 5 6 7 8 9 is closer to 90

shrugs

really I don't understand why they do it that way, to me 89 is 89

 

So how many places would you go? Let's say the teacher is putting together the semester average. So you have the three six-weeks grades and the exam grade. If she got two 89.49s that rounded down to 89, then she would have an 89, right? But 89.49+89.49=178.98. 178.98 rounds up to 179 though. And 179 deivided by 2 equals 89.5. That rounds up to 90. So that could have possibly happened to your sister.

 

No! 89 is not 89. 89 is 90, that is final. I shall never admit defeat!

 

It doesnt matter! What happened was by sister got a B+ in the class, but she refused to believe that. So she E-Mailed her professor and said that 89.49 rounds up to 90 so she should get an A-. The professor said "oh yeah you're right, sorry I'll change it" and then changed it. My sister believes that she earned an A, and BECAUSE OF THAT she argues that this must be the way it works. I quote her: "in some other context, id admit u r right, but not when were talking about whether or not i should get an a or a b"

 

The fact that her teacher didn't notice and she got away with it is reason enough for her to get the A, I'd say.

 

Yeah, thats what I said.

 

"Freedom is the freedom to say that two and two make four. If that is granted, all else follows."

[/1984]

 

You made your sister cry?

 

Stop rounding on your sister.

 

I'm going to be a huge nerd (again): errors like that really annoy people who mark lab reports etc. The general rule of thumb is to not round anything until you've reached your final answer, otherwise you lose information and get the result you just showed to us.

 

The professor was wrong, but hey, your sister benefitted from his mistake.

 

I thought this was going to be about the underground poker circuit.

John Malkovich has a really bad Russian accent, btw.



Go n-ithe an cat thú, is go n-ithe an diabhal an cat.

 

You're not the boss of me. Come back when you have definitive answers and not just guessings, mr. mcsmartypants.

 

wha? I thought...oh crap now I failed my math test...thanks IJG

 

#$%#%# DAMN IT IM NOT JUST GUESSING!!!