Manasara 45.37

45.37

ṣaṭsaptāṣṭakavṛddhyā tu dvādaśa kṣapayed budhaḥ
śeṣamāyamiti proktaṃ saptāṣṭanavavardhanāt

With an increase of six, seven, or eight, the wise one should divide by twelve; / the remainder is declared as the āya (gain). Increasing by seven, eight, or nine,