Which dynasty and century did the abacus first come from?

The origin of abacus can be traced back to the 6th century BC. It is said that there was a "calculation board" in China at that time. The ancients strung 10 abacus beads into a group, arranged them in groups, put them in boxes, and then quickly set aside the abacus beads for calculation. At the end of the Eastern Han Dynasty, Xu Yue recorded in "Numerology Legacy" that when his teacher Liu Hong visited the hermit Mr. Tianmu, Mr. Tianmu explained 14 calculation methods, one of which was abacus, and the calculation tools used were very close to modern abacus. Each abacus has five active beads, the upper 1 is equivalent to 5, and the lower four are regarded as 1 respectively.