Posts Tagged ‘calculation’

Fast multiplication

Sunday, June 28th, 2009

learn how to multiply 2-digit numbers without using a calcultor. it works!!

Duration : 0:5:1

(more…)

Abacus Subtraction

Friday, May 29th, 2009

A demonstration of how to use the abacus for calculating subtraction equations.

Duration : 0:1:20

(more…)