Little is known about Lee Kai-chen. This manual gives no information about him or how he came to invent his abacus. All remains a mystery.

About the abacus he created, however, we do know a little more. During the middle part of the last century Lee produced a small number of extraordinary and unusual abaci. The Lee Kai-chen Abacus was made in Taiwan where it was manufactured for only a few years. Manuals show 1959 as the copyright date for the abacus and June and December 1958 as printing dates for the manual.

Although the manuals that accompany his abaci seem to have remained largely unchanged, the abacus itself did go through a number of design modifications. Whether or not these modifications were a conscious effort to improve the abacus or whether it was a manufacturing decision is unclear. Perhaps the answer lies somewhere in between.

This book has 58 pages and it’s in excellent condition