Excel 2007: Sum Not Updating When Changing Values – Manual Calculation Mode Issue

Hello - could you please help me? I have a problem with Excel 2007, well: I enter numerical values into Excel - it gives a summation (sums me up) but when I change the values or add another, it does not change the previously calculated value, i.e. it remains as it was -> for example, it enters: 2 2 2 2 2 - -> excel calculates that it is 10 ---> I change now to 2 3 2 2 2 -> and exscel instead of changing the value to 11, it has 10
if I make a new excel file, it is fine and everything changes - but I can't convert to another file because I have had this one for 5 years and I have everything in it there. How to fix it ?

Upload said file.

Unable to put .xcls file -> I can send to e-mail

But packed (RAR, ZIP) it is possible.

Try to select the whole area you are adding up, then right click and select Format Cells / Numbers / Numeric and OK - it should help.
kisses

Or maybe you have automatic recalculation turned off.

Change the number and press F9

If it recalculates, check the options automatically instead of manual recalculation.
[in 2010 tab file / options / formulas block "calculation options"]

you can edit the cell value and confirm with enter ... then it obtains the general format ...