The Yupana was an ancient calculating device of the Incas. This simple program compares different theories:
- positional notation
* Base 10 by H. Wassen
(representation, addition)
* Base 10 by C. Radicati di Primeglio
(representation, addition, subtraction, multiplication)
* Base 10 by W. Burns Glynn
(representation, addition, multiplication)
* Base 40 by N. De Pasquale
(representation)
- sign-value notation
* Powers of ten by C. Florio
...