China’s ambassador to the world
Aditya Rishi

This is six

MR ROCESSOR ‘the computer’, to Later ‘the calculator’: "Count; is that all Abacus Abu can do?" Later: "It can add as well; to add 6 and 5, we represent 6 by adding 5 and 1 (one 5-bead in the 1’s column and one 1-bead in the 1’s column)."

Later (continues): "To add five to it, bring down the other 5-bead in the 1’s column as well. Adding 5 requires a carry of 1 (one 1-bead) to the column on the left (in the 10s column). We reset the upper deck and obtain the answer from the middle bar (10 in the 10s column + 1 in the 1’s column = 11)"

Computer: "Where was Abu born?" The present abacus appeared in about 1200 AD in China; it is called suan-pan in Chinese. On each rod, classic Chinese abacus has 2 beads on the upper deck and 5 on the lower deck; such an abacus is also called a 2/5 abacus. The 2/5 style survived unchanged until about 1850, when the 1/5 (one bead in the top deck and five beads in the bottom deck) abacus appeared. 

In about 1600 AD, the use and evolution of the Chinese 1/5 abacus was started by the Japanese via Korea. The abacus is called soroban in Japanese. The 1/4 abacus appeared in Japan close to 1930. The 1/5 models are rare and 2/5 models are rare outside China. Early Christians brought abacus to the East." (To be continued; write at The Tribune or adityarishi99@yahoo.co.in)