We are only supposed to take the following or you can follow this method:-
1) Take the Fair Value of Investment 2) Take the Fair Value of Net Assets acquired that’s basically the (100% of the Net Assets Multiplied by Net Assets of Subsidiary at the time of Acquisition) 3) Deduct the Fair Value of Net Assets acquired from Fair Value of Investment.
With this you will find the goodwill for reporting date. Remember if there is impairment you are supposed to deduct that too from the Investment.