Surya Siddhanta
ग्राह्यग्राहकयोगार्धात् प्रोज्झ्येष्टग्रासम् आगतम् । अवशिष्टाङ्गुलसमाम् शलाकाम् मध्यबिन्दुतः॥
From half the sum of the eclipsed and eclipsing bodies subtract the amount of obscuration, as calculated for any given time : take a little stick equal to the remainder, in digits, and, from the central point.
english translation
grAhyagrAhakayogArdhAt projjhyeSTagrAsam Agatam । avaziSTAGgulasamAm zalAkAm madhyabindutaH॥
hk transliteration by Sanscript