Universal Calculator

Purpose and user intent: a multi-field calculator designed for quick, reliable numeric tasks. Primary users include students, engineers, scientists, data analysts, and professionals who validate formulas or compare values. It is used for basic arithmetic, algebraic expressions, and multi-step computations outside a spreadsheet, or when a standalone evaluator is preferred for clarity and speed.

Core logic and features: required features include input validation for numeric operands, an operator selector, support for at least add, subtract, multiply, divide, and power, and a result display with configurable precision. Optional features include parentheses handling, exponentials and roots, basic trig functions, memory store/recall, expression-based evaluation, and a calculation history. Deterministic evaluation uses standard operator precedence. For example: (3+5)*2 = 16; 2^10 = 1024.

Inputs and outputs: inputs include operand_a (number, required), operand_b (number, optional for unary ops), operator (enum such as add, subtract, multiply, divide, power, sqrt, log, cbrt; required if no expression), expression (string, optional, sample "(12+5)*3"), precision (integer 0–15, optional). Output: result (number, no units, formatted with given precision or default 6 decimals).

Algorithms and calculations: uses standard arithmetic rules with explicit precedence for exponentiation and parentheses. If an expression is provided, a safe parser evaluates it; otherwise a single operation is computed. Division by zero yields an error state, invalid tokens yield an error, and numeric overflow yields NaN or capped display.

Error and edge cases: missing required inputs cause error state; non-numeric inputs invalid; division by zero; extremely large values; expressions with undefined tokens return error. Industry, region and localization: default to dot decimal separator, locale-agnostic; supports basic SI-like numeric formats. Assumptions and exclusions: decimal numbers only; no statistical functions, graphing, or unit conversions; memory features are optional and not mandatory.