Aritmetika is the first arithmetic textbook published in Bulgarian and the first textbook written by Khristaki Pavlovich (1804−48). It was widely used in 19th century Bulgaria. The book covers basic arithmetic, but it also includes instructions on calculating dates of various Orthodox holidays using a device called ruka paskhalna (a palm to calculate the dates of Easter) or ruka mesiachna (a palm to calculate the days in a month). These devices are also known as Damascene hands or hands of Damascus. The book was published in Serbia, which had attained autonomy within the Ottoman Empire and where a royal Serbian publishing house for the printing of Slavic books had been established. At the time, the Bulgarians did not have autonomy or their own publishing house, but the Serbian prince allowed some Bulgarians to produce books written in Bulgarian at the Serbian press in Belgrade. The author of this work, Khristaki Pavlovich, was born in the town of Dupnitsa. He became a monk at the Rila monastery and later a teacher in Svishtov. Among his pupils were luminaries of Bulgarian history such as Petko Slaveikov and Dragan Tsankov. He wrote or translated many books, including a famous Slaveno-Bulgarian grammar and his edition of Paisii Khilendarski’s Book of Kings or a Bulgarian History, Which Teaches from Whence Came the Bulgarians, How They Became Rulers, How They Reigned and How Their Kingdom Perished and Fell under the Yoke.