Abacus is a general purpose calculator, with a few added specialised functions. The distinguishing features of Abacus are…
1. Complex numbers
2. Multiple memories
3. Programmable
4. Calculations using Roman numerals
5. Calculations using pounds, shillings and pence
6. Calculations with angles expressed in degree,
minutes, seconds
7. Binary, octal and hexadecimal calculations
8. Statistics calculations