A Work by the Illustrious Brahmagupta

...the obtained degrees and minutes added to the Sun gives the mean Moon or corrected mean position. That is the meaning.

Now, the manual: When the day-count is being made, the number of days given starting from the month are multiplied by 12. When divided by 30, these become signs. Thus, the signs and degrees are to be added to the Sun in the second position. Then, keeping the previously obtained remainder of the lost lunar days as it is, multiply it by 3 and divide by 173. The resulting degrees, etc., become the result. Added to the Sun, which is combined with the days, it becomes the mean Moon. Thus, the mean Sun and Moon at midnight in Lanka are obtained.

Now, an example: When the day-count is being calculated, the days given are 11. These, multiplied by 12, are 132. Divided by 30, the signs are on top, and degrees are below: 4 signs, 12 degrees. These, added to the mean Sun, [0 signs, 28 degrees, 38 minutes, 16 seconds] result in [5 signs, 10 degrees, 38 minutes, 16 seconds]. The previously obtained remainder of the lost lunar days is 402;56;46. This, multiplied by 3, is 1208;50;18. When divided by 173, the obtained degrees are 16. The remainder, multiplied by 60 and divided by the same 173, gives 58 minutes. Again, the remainder, multiplied by 60 and divided by the same 173, gives 15 seconds. Thus, the result in degrees, etc., is 4 degrees, 58 minutes, 15 seconds. Adding this to the previously calculated Sun [5 signs, 10 degrees, 38 minutes, 16 seconds] results in the midnight mean Moon: 5 signs, 17 degrees, 37 minutes, 31 seconds. In this way, everything should be calculated. The Sun is from the day-count. Now, he describes the calculation of the Moon from the day-count.

Multiplied by 600, divided by 417... original: "khakharasagunitāt saptarāmśamunīndukṛtādhikāt jinavaguṇāṣṭihatāt. bhagakhādirvā himāmśurnavamatānaih kalārahitah" ||10||

Meaning of the verse: From the total day-count. "Khakharasagunitat" means zero, zero, and six the number 600. Multiplied by that. From the result, "Saptaramśamunindukrtadhikat" means the divisor.