Consolidation of investment

Hi,

Like to know the different methods available in Consolidation of Investment and calcuation of Non-controling Interest.

One of the scenario, in my current organization.

We have a Parent company P1000 and Subsidary companies S2000 and S2001

P1000 has invest different share percentages to develop the subsidary companies for ex

P1000 invest 56% on S2000

P1000 Invest 73% on S2001  etc..

P1000 is a listed company and subsidaries are not.

Now if i adopt a method for Consolidation of Investment it will be Equity method or Purchase method.

your help on this will be highly appreciated.

thanks and regards

Praveen.J