PocketPlay
中文
Calculator
A standard and scientific calculator that evaluates whole expressions, with degrees or radians, memory keys and a history list.
Type straight into the expression line: digits, + − × ÷, ^ for powers, ! for factorial, sin/cos/tan/ln/log/sqrt, pi and e. Enter calculates, Esc clears.
History
Results you calculate appear here — tap one to reuse it.
How to use the calculator
- Type or tap a whole expression such as
2+3*4^2— the running result appears under it as you type, so you can see a mistake before pressing equals. - Switch between DEG and RAD before using sin, cos or tan; in degrees
sin(90)is exactly 1. - Press = to push the result into the history list on the right; click any history line to put it back into the expression.
FAQ
Which functions can I type?
sin, cos, tan, asin, acos, atan and their hyperbolic forms, ln (natural log), log (base 10), log2, sqrt, cbrt, abs, exp, round, floor, ceil, sign, pow(a,b), mod(a,b) and rand(). The constants pi and e are available, ^ raises to a power, ! is factorial and a trailing % divides by 100.
How is the expression evaluated?
With a shunting-yard parser written for this page — the expression is turned into postfix notation and evaluated step by step. The browser's eval is never used, so nothing you type can run as code.
Why does 0.1+0.2 show 0.3?
The result is rounded to 12 significant digits for display, which hides the tiny binary floating-point error that every computer has. Long chains of operations may still drift in the last digit.