Comment 2 for bug 707923

I first encountered that problem with a Lexware software.

There are two ways to calculate the tax:
- by columns (vertical)
- by lines (horizontal)

Lexware (and obviously OpenERP) use horizontal calculations, while the most common usage is vertical.

So the totals are, while feeling wrong, actually correct.

(German link)
http://support.lexware.de/portal_support/00897-0000/supportProductFAQDetail?ID=000000000015732&searchTerms=&area=&version=2008&batchStart:int=40

In Germany, both ways are accepted by tax offices.
I don't know about other countries.

In you picture:

A * B = C
1,99 * 0,1 = 0,20
0,38 * 0,1 = 0,04
5,68 * 0,1 = 0,57
0,45 * 0,1 = 0,05
1,05 * 0,1 = 0,11
2,87 * 0,1 = 0,29

SUM(C) => 1,26

while

SUM(A) = 12,42
* 0,1 = 1,24