Cranmer Abacus, Abacuses for the Blind or Visually Impaired
Basic Definition - Cranmer Abacus, Abacuses for the Blind or Visually Impaired It is an abacus invented by Tim Cranmer, hence its name, commonly called Cranmer Abacus is still commonly used by people who are blind, visually limited or blind. Cranmer Abacus Features - Cranmer Abacus, Abacuses for the Blind or Visually Impaired One of the main features of the abacus, is that the spheres, counting seeds or pearls, not be moved without the user does, in order to avoid it and facilitate transactions with this, Tim Cranmer, devised a mechanism to jam it or curb these areas, seeds or beads in order to facilitate handling of same, A soft cloth or rubber is placed behind the beads so that they do not move inadvertently. This prevents the grains move from place while the users feel to manipulate, usually blind users, in order to use the abacus with precision, to perform mathematical functions multiplication, division, addition, subtraction, square root and cube root. ...