Associated Topics || Dr. Math Home || Search Dr. Math

### Rounding Up or Down on a 5

```
Date: 06/13/99 at 20:16:54
From: Pat Slaber
Subject: Rounding up or down on a 5

We are having a disagreement in our family - my children are being
taught always to round up if the adjacent number is 5 or more. My
husband agrees. I was taught that if the number is, say 7.5, to round
up to the whole number it would be 8. But if the number is 6.5, you
would round down to the 6. This is because the 5 is smack in the
middle and if you always rounded up on the 5, things would eventually
get inflated and the even/odd rule kind of balances this out. I notice
in your archives that you always round up on the 5. Do I have to back
off on this argument?
```

```
Date: 06/14/99 at 15:17:56
From: Doctor Terrel
Subject: Re: Rounding up or down on a 5

Hi Pat,

Don't back down. But let's ask the proper question here: when and for
what purpose are you rounding numerical values? Your mention of
"sometimes up and sometimes down" is especially useful, perhaps even
advisable, when dealing with a long list of data, say as an accountant
might have. There, your idea of "the even/odd rule kind of balances
this out." makes good sense, doesn't it?

But if you only have one data point to consider, as in a measurement
of a length (which wouldn't be exact anyway), we have to deal with a
compromise here. Tradition the favors the round up idea - check with
how all scientific calculators round (with their "fix" function.)

I'd say you're both right. It just depends what the situation is.

Will this bring peace to the family?

- Doctor Terrel, The Math Forum
http://mathforum.org/dr.math/
```
Associated Topics:
Elementary Fractions
Elementary Place Value

Search the Dr. Math Library:

 Find items containing (put spaces between keywords):   Click only once for faster results: [ Choose "whole words" when searching for a word like age.] all keywords, in any order at least one, that exact phrase parts of words whole words

Submit your own question to Dr. Math
Math Forum Home || Math Library || Quick Reference || Math Forum Search