Basic Calculator

An basic arithmetic calculator performs the four fundamental operations — addition, subtraction, multiplication, and division — on real numbers. When you tap a digit, it appears in the expression line at the top of the display. Operators such as +, −, ×, and ÷ tell the calculator which operation to apply between the current value and the next number you enter. Pressing equals evaluates the full expression using standard order of operations: parentheses first, then exponents, then multiplication and division (left to right), then addition and subtraction (left to right).

The percent key interprets the following value as a percentage of the current operand. For example, 200 + 10% computes 10% of 200 and adds it, yielding 220. The ± key toggles the sign of the displayed value, which is useful for entering negative numbers without a dedicated minus key during number entry.

Memory functions follow the classic MR/MC/M+/M− convention. M+ adds the displayed value to memory, M− subtracts it, MR recalls the stored value into your expression, and MC clears memory to zero. Parentheses let you group sub-expressions so that inner calculations are performed before outer ones — essential for problems like (8 + 2) × 5 = 50.

AC (All Clear) resets the entire calculator including the expression, while C clears only the current entry. Backspace removes the last character from the expression. Keyboard shortcuts mirror the on-screen buttons: type digits and operators directly, press Enter for equals, Escape for AC, and Backspace to delete one character.

The history panel below the keypad stores your last ten completed calculations in the form "expression = result", making it easy to verify homework or reuse a recent answer. This calculator uses JavaScript's built-in Math library for floating-point evaluation and displays results with sensible rounding for everyday use.