Problem with formate of cells, can't change it, any suggestions?

Hello!

I have a generated sheet with some data, now I need to make some calculations in the sheet, but some of the values have a format that is not a number, and I can't change them to numbers by just rightclick - format cells and choosing numbers, cpy and using special paste doesn't work either. Somehow numbers above a thousand get that kind of format.
Now any ideas on what to do, in the picture below, column P and Q are the ones with the problems, In U and V I just tried to demonstrate a simple calculation.

excel_problem.jpg

Sincerely