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Rounding numbers ending in 5

Posted: Sat Oct 06, 2018 12:41 pm
Hi,

I am currently reading Appendix 1C in our textbook about scientific notation. It says that when rounding off numbers ending in 5, the number should be rounded to the "nearest even number." For example, 2.65 would be rounded to 2.6. I feel very much like I have been lied to my entire life, because I have always been taught to round up for numbers ending in 5 and higher. I'm just wondering what rounding rules other people follow and whether the "to the nearest even number" is what I should be using for numbers ending in 5. Thanks so much for any help!

Re: Rounding numbers ending in 5

Posted: Sat Oct 06, 2018 12:54 pm
I believe it is more standard to round up with numbers ending in 5

Re: Rounding numbers ending in 5

Posted: Sat Oct 06, 2018 1:13 pm
I have always been taught to round up numbers ending in 5 as well.

Re: Rounding numbers ending in 5

Posted: Sat Oct 06, 2018 1:35 pm
I believe the text book is covering the rounding that is used in banking and possibly in chem labs, it makes the numbers more easier to work with.

You should keep rounding the way you have been taught.

Re: Rounding numbers ending in 5

Posted: Sat Oct 06, 2018 2:08 pm
I would continue to go with what you were taught with in the fact that you should round up if you have a number ending with 5. Therefore if it was 2.65 I would round it to 2.7 still. If you are still really unsure I would go ask a TA but I'm sure they'll tell you that it's okay to round up! Hope this helps.

Re: Rounding numbers ending in 5

Posted: Sat Oct 06, 2018 8:01 pm
All of the textbook solutions in the solution manual round up when dealing with calculations ending in 5 so I would definitely say that's the way to go.

Re: Rounding numbers ending in 5

Posted: Sat Oct 06, 2018 8:20 pm
Personally, I have always used the method of rounding up whenever the ending number is above 5, so I think you should be good. For your specific example, I would have rounded 2.65 to 2.7.

Re: Rounding numbers ending in 5

Posted: Sat Oct 06, 2018 9:16 pm
I can't really think of why the even number would be favored. I would just round up to the next number (2.7).

Re: Rounding numbers ending in 5

Posted: Sun Oct 07, 2018 3:06 pm
I usually use the most exact number (from the calculator) when dealing with the problem, and at the very end, I round to however many significant figures there are given from the problem.

Re: Rounding numbers ending in 5

Posted: Sun Oct 07, 2018 6:12 pm
I have once been told that if the number were something like 2.652 and I had to round to the 1st decimal place, it would be rounded to 2.6, but I have never really payed attention to that rule. Typically, I would still round to 2.7.