Arithmetic () is a 1703 mathematics textbook by the Russian educator and mathematician Leonty Magnitsky. The book served as the standard Russian mathematics textbook until the mid-18th century. Mikhail Lomonosov was educated on this book, and referred to it as the "gates of my own erudition". It was the first mathematics textbook written in the Russian language that was not a translated edition of a foreign work. It consisted essentially of Magnitsky's own lecture notes, and offered an encyclopedic overview of arithmetic at the time, with sections on navigational astronomy, geodesy, algebra, geometry, and trigonometry.
