Fingers
i am used to count some call this a manual calculator it's also called abacus
There is no such number on a calculator. If you see "R" on a calculator, it is probably some calculation - for example, conversion from polar to rectangular coordinates. Check the manual for your calculator.
The answer depends on what functions are built into your calculator. Read the calculator manual.
by reading the manual
Abacus
abacus is the first manual mechanical calculator
'Ganak'.
abacus
Not quite sure what you want; the calculator only shows a limited number of decimals in any case. Some calculators have options to round the result to a certain number of decimal places. If that's what you want, check your calculator's manual for details.
A virtual calculator can be implemented using VHDL. We call it VHDL calculator.
Usually a graphing calculator should have all the capabilities you expect from a scientific calculator (and more, since it does the graphing). For more details, check the manual of your calculator if you already have one.