The Compact Scientific Calculator 54 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-54 and sin(2*1E20*pi)=0+-1E-34. As we see, the result’s accuracy degrades with growth of argument, but such approach allows to preserve all trigonometry facts like sin(even number*pi+x)=sin(x).In the default mixed mode the calculator treats numbers as integers wherever it is possible. For example, 49! have an integer result with 63 digits. By the way, 63 digits is the internal precision of calculations. This is 7 super-digits, where a super-digit has 9 decimal digits.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.Limitations: