Created attachment 118924 [details] Screenshot I tried to make a calculation of a flat square meters following 2 different ways and i got 2 different results. According to the CAD the right one is 42,94 sq.
The operation is different. In Excel, copying the exact first line, I've got the same result as LibreOffice =(1,14+1,5)*4,23+1,68*1,03+9,63*3,25+0,35*3,6-0,34*1,54 44,9315 so it may correspond to your result if you formatted the cell with 2 decimals.