|"The digits are set on an abacus in the
same order as they are read, for example 765 rubles, starting from the leftmost digit.
At first it is necessary to put the abacus in such an angle on the desk that the direction of the right hand movement coincides with the wires of the abacus. This is similar to the direction of a book or a sheet of a paper where you are writing. Before the beginning of the work all beads are moved to the right edge of the abacus.
While moving a bead from right to left it is kept between the index finger and the middle finger of the right hand.
The movement of the beads by one finger is not recommended because one finger can easily slide off a bead.
To reset the beads to a former situation at the right edge of the abacus needed in some arithmetical operations, it is convenient to use the thumb.
For example to enter number 5874 starting from the first digit, it is necessary to move to the left edge in the eight wire 5 beads, in the seventh wire 8 beads etc."
Translated by Sergei Frolov and Timo Leipala from: Schadrina, "Trade calculations". Learning book for colleges. Moscow, "Economika", 1986.
Photo is courtesy of: Sergei Frolov.