How to use this calculator
Use the keypad for arithmetic and the displayed scientific controls for powers, roots, logarithms and trigonometric functions. Check the angle mode before using sin, cos or tan, and clear the calculation before starting an unrelated expression.
Method and interpretation
DEG interprets angles in degrees; RAD interprets them in radians. Natural logarithm uses base e, while the ordinary log control uses base 10. Factorial multiplies positive integers down to 1, with 0! equal to 1.
Assumptions and limits
Calculations use ordinary JavaScript floating-point numbers, so displayed decimals may be rounded. A real square root requires a nonnegative value and real logarithms require positive values. Factorial accepts nonnegative whole numbers within a finite numeric range. This is a keypad calculator, not a general algebra proof engine.
Worked example
In degree mode, sin(30) is 0.5. The same numeric input in radian mode represents a different angle. For a separate factorial example, 5! equals 5 × 4 × 3 × 2 × 1 = 120.