Math problems

[marshal...@gmail.com]

Does anyone get these kinds of math problems on their reports? What am
I missing?

Task Wk 1 Wk 2 Wk 3 Wk 4 Wk 5 Total Hours
COR-001
6.5 6.5
NEX-018
4.6 4.6
NEX-019 7.6 5.2 3.0
15.7
ZZZ
0.7 0.7
Total 6.5 5.3 7.6 5.2 3.0
27.3

The 15.7 Should be 15.8, and the final total should be 27.6 not 27.3.
What's going on? I know it's probably something easy, but I'd feel a
lot better if I knew I could trust Slim Timer's math. I get these
kinds of addition problems on all my reports.

-Me

[marshal...@gmail.com]

sorry for the broken table. Does this work?

[Cori Schlegel]

Unless I'm much mistaken, you're seeing rounding in action.

Your 15.8 is true for the total of the 3 weeks in question, but if the
real, not rounded numbers are 7.56 and 5.17 then you end up with 15.73
as a total, which rounds to 15.7. I also believe that each total totals
and rounds separately, which could explain the larger discrepancy
between the weekly totals and the grand total - the grand total isn't
the sum of the weekly totals, it's the sum of the actual time of the
tasks that make up the weekly total, rounded to the nearest 10th.

cori schlegel
http://kinrowan.net
AIM/Yahoo/Skype: corischlegel
Identica: http://identi.ca/cori