You can enter expressions (e.g. "100e-9*100e-9/sin(pi/2)") and use SI number postfixes (e.g. "1k" or "4.7n"). Variables name when set can be used in the input. To overwrite a variable, save a new one with the same name. Available functions: abs, acos, asin, atan, ceil, cos, exp, floor, log (base 10), ln, round, sin, sqrt, cbrt, tan. Functions pow, min, and max take two arguments, e.g. pow(2,5) = 32. Function hypot returns the sqrt of the sum of the arguments squared, e.g hypot(3,4)=5 and hypot(3,4,5) = 7.071. Constants are: pi, tau, e, and rand. Use the up and down arrows to scroll equation history. randint(min,max) gives a random interger between min and max inclusive, e.g. randint(1,6) is a dice roll. randfloat(min,max) gives a random float between min (inclusive) and max (exclusive). Brackets are auto-closed at the end of the equation if left open. function fact give factorials, fact(5) = 120, up to fact(170). nCr(n,k) and nPr(n,k) are Combination (binomial) and permutation. Functions sum, mean, median, mode, std, vari, stderror are the basic statistical functions, mean(1,2,3,4) = 2.5, sum(1,2,3) = 6etc.