Why the excel does not update the formula | Excel Formula not working

When excel formula not worked, the workbook has been placed in "Manual calculation" Mode, which means excel will not update all the formulas, whenever you update the workbook, it manuallay forced to do so.
It can also effect copying, as when you copy and paste a formula, the result will be copied instead of the correct answer, it would not automatically update, so we have to perform manual calcualtion and use it's prompt.

How to solve it We have to force a manual calcualtion.
Turn it back to automatic.
It has to be noticed that manual calculation is performed only when you have large data and you have to speed up the calculations.
1. Force a Manual calucation by pressing F9
2. Swith your workbook back to automatic from Formulas => Calculation options.
It solves most of our problems like Formula not calculating in excel
Formula not calculating correctly in excel
Formula not calculating in cells
Formula not calculating showing as text
Formula is not working in Excel
We can solve most of our issues of calucation from the above methods.