Narada Purana (Jyotisha Selections) · by Vyasa
Chapter 2 · Signs, Planets, Birth
जातकम् १
हित्वा भाज्यंगभागादीन्कलीकृत्य खखाक्षिभिः ।भजेद्वर्षाणि शेषे तु गुणिते द्वादशादिभिः ॥ १२८ ॥
In the full Narada Purana (Purva Bhaga) this is chapter 55, verse 128.
Leave aside the signs. Turn the degrees and the rest of the lagna (rising sign) into minutes. Divide by 200 to get years. Multiply the remainder by 12 and so on.
Simple meaning: The rising sign's degrees are turned into minutes and divided to give years.
द्विसप्तांशे च मासादिलग्नायुर्जायते स्फुटम् ।
A step to find the rising sign's life in months, and to start the degree method.
खयुगैरायुरंशाः स्युस्तत्संस्कारं वदामि ते ।
A correction is made only in a certain case.
तदंशः स्वाग्नयो भक्ता लब्धोनोभूर्गुणो भवेत् ।
A multiplier is worked out by dividing parts by thirty.