TextCalc is a very useful and powerful program that allows you to write and solve advanced problems.
Its main advantage is its text editor where you can write different expressions, solve them, and make annotations all in the same window. The information in the editor window can be copied and pasted to other applications. You can include operators in your expressions, e.g., (3+2)*4/2*sin(3.141592653589793/6). You can type many numbers separated by spaces, create a list of numbers, or select a block of text that includes numbers and sum them with the Sum feature. With the "Apply numbers" feature you can multiply by a factor, add a value, or type any expression to evaluate every number on a list. Other predefined functions you can use with a list of numbers are: Average, count items, sum of squares, root mean squares median, find min and max values, mean deviation from mean standard deviation, and variance. You can also convert decimal numbers to hexadecimal, octagonal, hex to decimal, etc. Other math functions included are: sine, cosine, tangent, hyperbolic sine, hyperbolic cosine, hyperbolic tangent, square, root, factorial, and more. Some aspects to consider: the spaces in expressions with operators are automatically removed and all the adjacent numbers are considered to be a part of the same number, TextCalc doesn't recognize numbers that have contiguous letters, the conversion feature is limited to positive integers only.