Arithmometer is a manual calculating machine designed to perform arithmetic operations, primarily division and multiplication. Felix was the most widespread arithmometer in the USSR. Выпускался с 1929 на трех заводах счетных машин: в Курске, Пензе и Москве. with the initial sale price standing at RUB 110 (before denomination). The arithmometer production peaked in 1968: a total of about 300,000 Felix and VK-1 calculators were manufactured that year. At the end of the arithmometer epoch, in 1978, their sale price dropped to RUB 15. At that very time, the Electronica B3-18A calculators were selling at RUB 220. With an average engineer earning around RUB 120–140, people would massively opt for arithmometers. In the late 1970-s and the early 1980-s, electronic calculators ultimately squeezed arithmometers out of the market.
The calculation range of Felix’s setting plate covers 9 digits, whereas the ranges of its result and revolution counters are extended to embrace 13 and 8 digits respectively.
The setting plate consisting of toothed washers (with a varying number of teeth) assembled around a common axis in the shape of a cylinder is located within the fixed frame of the machine.
The machine box has 9 slots featuring setting slides (117), which are used to input numbers for calculation.
The horizontal row of digits over the slots ranging from 1 to 9 indicates the position of input numbers; the point sign, or position indicator (51), is located further up the line.
The result (301) and the revolution (3) counters are placed inside a movable carriage (3).
Just above the rectangular slots of the carriage lid there are two horizontal lines of digits indicating the position of numbers provided by the counter and the wheel, whereas below the rectangular slots there is a line with movable points, i. e. the position indicators (51).
Performance: 115 operations per hour for the multiplication of five-digit numbers by four-digit ones, and 85 operations per hour for the division of five-digit numbers by four-digit ones.
Weight — 3.5 kg. Size — 275✕165✕132 mm.