The south-western province of Kerala in India is known for its important contributions to mathematical analysis and astronomy in the medieval period. What is termed the ‘Kerala school of astronomy and mathematics’ emerged during 14th –18th centuries. Karanapaddhati of Putumana Somayaji composed around 1730 CE is one of the important texts of this school. In the Indian astronomical tradition, the ‘Karana’ class of texts choose a recent epoch and outline only the computational procedures for planetary positions, diurnal quantities, eclipses etc., with the aid of arithmetical / algebraic expressions without presenting any theoretical framework. Karanapaddhati is a unique treatise in the Indian tradition of astronomy which aims at assisting astronomers in preparing karana texts , by giving the paddhati (method) for the algorithms.

The computation of the longitudes of the Moon and the planets involve the rates of motion of their mean longitudes and the zodiacal and solar anomalies (mandakendras and sighrakendras. Accurate computastions would involve ratios with large numerators or multipliers ( gunakaras) and large denominators or divisors ( harakas). Karanapaddhati expresses these ratios as continued fractions. The approximations to the exact ratios involve small multipliers and divisors . These small multipliers and divisors play a crucial role in the algorithms for generating the mnemonics or vakyas for the true longitudes of the Moon and the planets. There are relations among the multipliers and divisors arising out of the continued fraction method. Putumana Somayaji is ingenious in using them to formulate the algorithms.