Yes, Appsheet and Sheet have the same location 

I think this error is not due to the setting or anything else. When I enter data, the results initially display correctly. But, after synchronizing the data (about five seconds), the displayed results changed, automatically adding 2 zeros to the resu...

this is the two formulas used for the sum() 

I have change the location to US, Vietnam,... but it not working 

Thanks for your help.But my problem is Appsheet add 2 zero before the comma. Ex: The first line in pic1 and the last line in pic 4( googlesheet), the correct value is 44,00 (fourty four) - but Appsheet show 4.400,00 (4 thousand and 4 hundred).