Abacus

(noun.) a calculator that performs arithmetic functions by manually sliding counters on rods or in grooves.

(noun.) a tablet placed horizontally on top of the capital of a column as an aid in supporting the architrave.

塞西尔手打

• The next adding and calculating machine was an evolution from the digits of the human hand and is known as the abacus in China, and the soroban in Japan. 佚名. 神奇的知识之书.
• Addition, subtraction, multiplication, division, and even square and cube root can be performed on the abacus, and in the hands of a skilled operator considerable speed can be obtained. 佚名. 神奇的知识之书.
• The abacus may be defined as an arrangement of movable beads which slip along fixed rods, indicating by their arrangement some definite numerical quantity. 佚名. 神奇的知识之书.

校对:奥菲莉娅