Empty disk: All gears of the abacus are in neutral, that is to say, there is no counting at all. This is called empty disk.
Inner beads: The counting beads counted by the light beam are called inner beads.
Outer beads: Counting beads that are not counted from the light beam are called outer beads.
Pull up: refers to pulling up the lower bead against the beam.
Pull: refers to pulling the upper bead towards the beam.
Pull out: refers to pulling the upper bead or the lower bead away from the beam.
This file: it is the file that corrects the number of strokes.
Previous gear: refers to the previous gear of this gear, also called left gear (bit).
Rear gear: refers to the rear gear of this gear, also called right gear (position).
Floating beads: the force is too light when pulling the beads, and the beads float in the middle of the file.
With beads: when pulling beads, call with beads to bring in or out the beads that should not be pulled in or out of this file or adjacent files.
Real beads: Beads that represent positive numbers with light beams.
Virtual bead: Also known as negative bead, it refers to a suspended bead that is not set as a beam or a border, indicating a negative number.
Set the number: also teach the number, according to the calculation requirements, dial the number into the abacus and prepare for calculation.
Gear: also called grade, it refers to the grade of gear.
Wrong gear: also known as dislocation, it means that the abacus does not dial the gear it should dial during the operation.
Shift: Also called shift, it refers to the second gear (position) of one gear left and right of this digit. In cross multiplication, two numbers are multiplied, and the number of digits of the product is played on the right two digits of the multiplicand; In each division, each quotient refers to the left two digits of the first dividend.