It evaluates a whole expression you type or build with the keys, such as 2^10 + sqrt(16) or 3sin(30)^2, and shows the answer while you type. It knows the four operations, powers, square roots, factorials, percent, natural and common logarithms, exp, absolute value and the six trigonometric functions, with the angle in degrees or radians. Results you finish with Enter or = go into a history you can click to reuse, the Ans key brings back the last answer, and the memory keys (MC, MR, M+, M−) keep a running total.
The expression is read by the calculator's own parser, one symbol at a time. It never runs your text as program code, so a typo cannot do anything except produce an error message.
How to use it
- Type into the expression box, or tap the keys. Functions need brackets:
sin(30), ln(2), sqrt(2). - Choose Degrees or Radians for the trigonometric functions. In degrees,
sin(30) is 0.5 and sin(180) is exactly 0. - Press Enter or = to finish. The answer replaces the expression so you can continue from it, and the line goes into the history. Escape or AC clears.
- Use M+ and M− to add the current result to memory or subtract it, MR to insert it and MC to clear it.
Decimals use a dot. A comma is refused with a message rather than guessed, because 1,5 could mean one and a half or a list of two numbers.
The order of operations, exactly
Calculators disagree on some expressions, so this one states its rules:
- Brackets first, then postfix
! and %, then powers, then a leading minus, then × and ÷, then + and −. - Powers group from the right:
2^3^2 is 2^9 = 512. - A leading minus applies after the power:
-3^2 is −9, (-3)^2 is 9, and 2^-3 is 0.125. - Implied multiplication, as in
2π or 2(1+2), is ordinary multiplication, done left to right with × and ÷. So 6÷2(1+2) is 6 ÷ 2 × 3 = 9. If you mean 1, write 6÷(2(1+2)). % only divides by 100: 200×15% is 30, but 50+10% is 50.1, not 55 as on a shop calculator.! works for whole numbers from 0 to 170; 2.5! is an error rather than a gamma-function value.
Why other calculators answer 1 or 55 is explained in why calculators disagree on order of operations.
Precision and errors
Numbers are double-precision floating point, the same as most software. The result is shown with 15 significant digits, which hides binary noise: 0.1+0.2 shows 0.3 and sqrt(2)^2 shows 2. Very large or small results switch to scientific notation (20! is 2.43290200817664e+18). In radians, sin(pi) is not exactly zero, because π itself is rounded; in degrees, whole multiples of 180 are exact.
Errors name the problem and the position: division by zero, an unclosed bracket, sqrt(-4), ln(0), asin(2), tan(90) in degrees, a result too large to show. While you type, a half-finished expression is not flagged; the message appears when you press Enter.
For percent of a total and percentage change with the formula spelled out, the percentage calculator is clearer.
