autosum addition error

[Will123]

when using autosum to add approx 30 cells of simple dollar amounts, it
calculates the total = a few cents short than the real amount- I can use a
calulator to get the correct amount. ie: example of amounts: 20,342.12 +
10,432.24 + 43,215.34 etc. thanks.

 

[Sheeloo]

Change the format and set the number of decimal places to more than two...
you may have more significant digits and what you see might be after rounding.

If you enter only two decimals then sum will always return the right result...

 

[JBeaucaire]

Rounding being missing from the original 30 cells is the culprit. Thi
happens a lot. Whatever formulas are in those 30 cells to creat
values, wrap then in a ROUND formula so the value you SEE in the cell i
stripped of any data past the first two digits

Then you can sum those cells with no problems

Example

=A1/B2*C3 might equal 1,234.5478
Displays as 1,234.55, but the .00789 is still there

Make the formula =ROUND(A1/B2*C3,2) instead, and the result is 1,234.5
for real

 

[Shane Devenshire]

Hi,

If your numbers a calculated (formula) then the problem may be:

Computers work in binary, we work in decimals

Here is everything you need to know about this issue (and more):

http://support.microsoft.com/kb/78113/en-us
http://support.microsoft.com/kb/42980
http://support.microsoft.com/kb/214118
http://www.cpearson.com/excel/rounding.htm
http://docs.sun.com/source/806-3568/ncg_goldberg.html