The
Cranmer Abacus was developed by T.V. Cranmer, in 1962. The abacus is known as
one of the best calculating tools for the blind and visually impaired.
The
Cranmer Abacus was developed by T.V. Cranmer, in 1962. The abacus is known as
one of the best calculating tools for the blind and visually impaired.
Students begin adding by one in kindergarten and first grade. By second and third grade, students add, subtract and later on multiple and divide. When proficiency is achieved, calculations can be done much quicker on the abacus than a sighted student achieves, using paper and pencil.
How to use: Looking to the far right (see abacus above), you will see 4 beads on the bottom and 1 on the top. The bottom 4 beads represent: 1, 2, 3, 4 (1 bead represents 1); the top bead represents 5. The student will set 1, 2, 3, 4 (moving the beads to the center bar), clear 4 (moving all beads to the bottom), set 5 (moving bead to the center bar).
As you move across the abacus (right to left), the rows are ones, tens, hundreds, thousands, etc.
Do you want to learn more about the abacus?
Using the Cranmer Abacus for the Blind, pulbished by American Printing House for the Blind in 1964, by Fred L. Gissioni
The Abacus Made Easy, by Mae E. Davidow, published 1966.
