@Patch@mick I think he wants to know how to get the amounts to values in order for him to do calculations on the spreadsheet. I do not think it can be done. I have experimented with it as well by changing the cell formats to numbers and so on, but no success.
Not sure what you want to copy and paste, but if for example, you searched for a set of payments under Payments, you can just with your mouse select all the data needed (excluding the edit and view buttons) and then for example sum the amounts (that works!). If anything, for any table representation in Manager inclusive of “Summary” you can select the data and copy and paste into Excel to further run calculations on.
Update: copy to clipboard a @Patch explains works as well, at least with Microsoft Excel version 16.49 for macOS. Are you sure you are using Excel as spreadsheet?
If for some reason Excel is not treating the digits as numerical values and will not respond to changing the number format via “Format Cells…”, something you can try is to select the cells affected, then choose Data > Text to Columns, then simply select “Finish” in the dialog box that opens.
Sorry, using Manager v21.5.37 on Ubuntu 20.04 Server and on macOS Catalina followed similar steps and had no problem copying and pasting and applying Sum(…) to selected numbers with Microsoft Excel version 16.49 for macOS. Can you please indicate similar information about Manager version and Excel version.
Update: Tried Libre Office v7.1.3 for macOS and no issues either.
We would like to see the formula that results in #VALUE! as the error is with the formula. So show us a full screenshot that includes the formula entry as in screenshot, obviously we need to see all the cells you try to sum.
Numbers imported as text often have a single quote as the first character in the cell.
Going in to the cell and deleting the quote or just editing the cell maybe enought to convert the string from a text string to a number.
Past special probably also gives you import options which are likely to help
Failing that a formula in excel =Value() or = NumberValue() will work