Abacus

The Abacus is the first calculator. THE BALLS OF OUR ABACUS FOLLOW A COLOR CRITERIA TO FACILITATE THE EXPLANATION of the most complex arithmetic operations. It also includes an elaborate GUIDE OF USE WHERE IS DETAILED THE PROCEDURE TO FOLLOW TO CARRY OUT ALL OPERATIONS Basic ARITHMETICS on the Abacus - SIDE. INCLUDES A MARKER that will help indicate the structure of the abacus the concepts that you want to reinforce (unds, tens, etc). Measures 36 x 39.5 21.5 cm