Hide the formular and auto-caculation if match conditions

[trucyeetung]

Hi All,
I got a form and supprise, just in case how to do automatic caculation after you input some cells,
pls find my excel file for more supprise and help to guide me.
Thank you very much and best regards,
Pls check file sample:

auto caculation excel.xlsx

drive.google.com

 

[trucyeetung]

Hi All,
If you input 1st and 2nd cells;
then 3rd cell automatic caculation base on above 2 cels results,
it's very easy if the 3rd cell have already write a formular,

But I got a file that the 3rd cell is empty and blank.
if you input other 2 cells, after that the 3rd cell give out a formular automaticly ...
how can to make it, can you help and guide
Thank you very much and best regards,

Pls check File sample

auto caculation excel.xlsx

1drv.ms