This calculator follows classical approach when uncertainty of f(x) calculation is estimated by formula max|(derivative(f))|*|x*uncertainty(x)|, where maximum of function derivative is considered on interval [x-uncertainty(x), x+uncertainty(x)]. Thus sin(2*pi)=0+-1E-90 and sin(2*1E20*pi)=0+-1E-70. As we see, the results accuracy degrades with growth of argument, but such approach allows to preserve all trigonometry facts like sin(even number*pi+x)=sin(x).

Scientific Calculator Precision 90 has internal precision 99 digits that allows to perform division (the most difficult operation) with precision 90 digits, standard functions (power, logarithm, trigonometric functions, hyperbolic functions) with precision 88-90 digits, and Gamma Function, Lower Incomplete Gamma Function, Upper Incomplete Gamma Function, Beta function, Incomplete Beta Function, Sine integral with precision 78-90 digits .

In the default mixed mode the calculator treats numbers as integers wherever it is possible.

Σ and Π has four levels of nesting.

There are 10 variables (or constants) available for storing frequently used numbers.

All calculation results are reflected in History rich-text-box, which can be saved in file or printed.

Unlimited number of user constants can be entered and maintained by user.

Fundamental constants are available in the prebuilt Common Constants list.