Calc Guide

symmetric arithmetic rounding: a decimal place of .4 or less gets
rounded down, while one of .5 or more gets rounded up. However, at
times, you may not want to follow these rules. For instance, if you are
one of those contractors who bills a full hour for any fraction of an
hour you work, you would want to always round up so you didn’t lose
any money. Conversely, you might choose to round down to give a
slight discount to a long-established customer. In these cases, you
might prefer to use ROUNDUP or ROUNDDOWN, which, as their
names suggest, round a number to the nearest integer above or below
it.
All three of these functions require the single argument of number—
the cell or number to be rounded. Used with only this argument, all
three functions round to the nearest whole number, so that 46.5 would
round to 47 with ROUND or ROUNDUP and 46 with ROUNDDOWN.
However, if you use the optional count argument, you can specify the
number of decimal places to include. For instance, if number was set to
1, then 48.65 would round to 48.7 with ROUND or ROUNDUP and to
48.6 with ROUNDDOWN.
As an alternative to ROUNDDOWN when working with decimals, you
can use TRUNC (short for truncate). It takes exactly the same
arguments as ROUNDDOWN, so which function you use is a matter of
choice. If you aren't working with decimals, you might choose to use
INT (short for integer), which takes only the number argument.
Another option is the ODD and EVEN pair of functions. ODD rounds up
to the nearest odd number if what is entered in the number argument
is a positive number, and rounds down if it is a negative number, while
EVEN does the same for an even number.
Options are the CEILING and FLOOR functions. As you can guess from
the names, CEILING rounds up and FLOOR rounds down. For both
functions, the number that they round to is determined by the closest
multiple of the number that you enter as the significance argument.
For instance, if your business insurance is billed by the work week, the
fact that you were only open three days one week would be irrelevant
to your costs; you would still be charged for an entire week, and
therefore might want to use CEILING in your monthly expenses.
Conversely, if you are building customized computers and completed
4.5 in a day, your client would only be interested in the number ready
to ship, so you might use FLOOR in a report of your progress. If cell E1
contains the value 46.7, =CEILING(E1;7) will return the value 49.
Besides number and significance, both CEILING and FLOOR include
an optional argument called mode, which takes a value of 0 or 1. If
214 OpenOffice.org 3.x Calc Guide