 The parivritti drekkana goes in order of the signs; the first decan is Aries, the second is Taurus, the third is Gemini, the fourth is Cancer, etc.Then there is the trinal calculation which utilizes the elemental trines to each sign; In Aries there is Aries, Leo, and Sagittarius, while in Taurus there is Taurus, Virgo, and Capricorn.There are in total four variations of drekkana calculations.