What the scientific calculator offers
A keypad calculator with the functions that a basic one lacks: trigonometry (sin, cos, tan), logarithms (log base 10 and natural log), powers and square roots, parentheses for grouping, and the constants π and e. It evaluates expressions with correct operator precedence rather than left-to-right, so 2 + 3 × 4 gives 14, as it should. It runs in your browser and works offline once loaded — useful when you have a laptop but no calculator.
Order of operations
1. Parentheses ( )
2. Functions and exponents sin, log, x², √
3. Multiplication and division × ÷ (left to right)
4. Addition and subtraction + − (left to right)
2 + 3 × 4 = 14 (not 20)
(2 + 3) × 4 = 20
2 × 3² = 18 (not 36)
−3² = −9 (the square binds tighter than the minus)
10 ÷ 2 × 5 = 25 (left to right, not 1)The last two lines catch people out most. If in doubt, add parentheses — they never hurt and make the intent explicit.
Function reference
| Key | Meaning | Example |
|---|---|---|
| sin, cos, tan | Trigonometric functions of an angle | sin(30°) = 0.5 |
| log | Logarithm base 10 | log(1000) = 3 |
| ln | Natural logarithm, base e | ln(e) = 1, ln(10) ≈ 2.3026 |
| x² | Square | 7² = 49 |
| √ | Square root | √144 = 12 |
| π | 3.14159265… | Circumference = 2πr |
| e | 2.71828182… | Continuous growth base |
| ( ) | Grouping | (1 + 2) × 3 = 9 |
Degrees or radians?
Trigonometric functions take an angle, and the same number means different things in degrees and radians: sin(30) is 0.5 in degrees but −0.988 in radians. A full circle is 360° or 2π radians, so 1 radian ≈ 57.3°. Most school and everyday problems are in degrees; calculus, physics and programming libraries (including JavaScript's Math.sin) use radians. Check which mode the calculator is in before trusting a trig result — a wrong-mode answer is the single most common scientific-calculator error.
radians = degrees × π ÷ 180 degrees = radians × 180 ÷ π
90° = π/2 ≈ 1.5708 rad 1 rad ≈ 57.2958°Useful identities and shortcuts
log(a × b) = log a + log bandlog(aⁿ) = n log a— how logarithms turn multiplication into addition.10^xundoeslog;e^xundoesln. To compute a logarithm in another base:log_b(x) = log(x) ÷ log(b).sin² + cos² = 1for any angle.tan = sin ÷ cos, undefined at 90° and 270°.- Percent change:
(new − old) ÷ old × 100. Compound growth:P × (1 + r)ⁿ. - Pythagoras:
c = √(a² + b²).
Precision and rounding
The calculator uses double-precision floating point, accurate to about 15–16 significant digits. Results like 0.1 + 0.2 = 0.30000000000000004 are a property of binary floating point, not a bug; round to the precision your problem needs. Very large intermediate values (above 10³⁰⁸) overflow to infinity and dividing by zero returns infinity or an error, as on a hardware calculator.