Title:
ABACUS WITH NOISE REDUCTION AND BEAD SHIFT PREVENTION FUNCTION
Document Type and Number:
Japanese Patent JP2011243215
Kind Code:
A
Abstract:
To provide an abacus with a noise reduction and bead shift prevention function in order to solve a disturbance to neighbors due to a noise caused by use of an abacus and an erroneous answer from a wrong calculation due to a shift of a position of a worked bead.
An abacus with a noise reduction and bead shift prevention function comprises a bead and a low repulsion material on inner sides of a frame and both sides of a bar with which a worked bead comes into contact, and on a bottom face of the abacus.
Inventors:
OSAWA SATOSHI
Application Number:
JP2011154303A
Publication Date:
December 01, 2011
Filing Date:
June 24, 2011
Export Citation:
Assignee:
OSAWA SATORU
International Classes:
G06C1/00