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Full-featured calculator with trigonometry, logarithms, and more
This calculator supports standard arithmetic operations plus advanced scientific functions. You can use your keyboard or click the buttons.
sin(30) returns 0.5 in degree mode and −0.988 in radian mode — both are correct for their mode, and only one is what you meant. Check DEG/RAD before you trust any trigonometric result.| Priority | Operation | BODMAS name | PEMDAS name |
|---|---|---|---|
| 1 | Brackets | Brackets | Parentheses |
| 2 | Powers and roots | Order | Exponents |
| 3 | Multiplication and division, left to right | Division, Multiplication | Multiplication, Division |
| 4 | Addition and subtraction, left to right | Addition, Subtraction | Addition, Subtraction |
BODMAS and PEMDAS describe the same rule with different mnemonics — multiplication and division share one priority level and are evaluated left to right, as do addition and subtraction. The mnemonics mislead people into thinking division comes before multiplication or vice versa. Where real ambiguity remains is implicit multiplication after a division: expressions like 6 ÷ 2(1+2) are read as 9 by most calculators and as 1 by some scientific models and by many physics conventions, which treat juxtaposition as binding tighter. There is no universally agreed answer; the fix is to write brackets and stop relying on convention.
| Function | What it does | Watch out for |
|---|---|---|
sin, cos, tan | Trigonometric ratios | Angle mode — DEG, RAD or GRAD |
asin, acos, atan | Inverse trig | Returns an angle in the current mode; range is restricted |
log | Logarithm base 10 | In most programming languages log means natural log |
ln | Natural logarithm, base e | Undefined for zero and negatives |
e^x | Exponential | Overflows quickly — e^710 exceeds double precision |
x! | Factorial | Integers only; 170! is near the floating-point limit |
nPr, nCr | Permutations, combinations | Order matters for P, not for C |
mod | Remainder | Sign of the result with negatives differs between systems |
± or (−) | Sign change | Distinct from the subtraction key on most calculators |
Evaluate 8 − 3 × 2² + (10 − 4) ÷ 3
Brackets first: (10 − 4) = 6
Powers: 2² = 4
Multiplication and division, left to right: 3 × 4 = 12, and 6 ÷ 3 = 2
Now addition and subtraction, left to right: 8 − 12 + 2
−2. Working strictly left to right from the start gives 14, which is the error most people make.
0.1 + 0.2 is not exactly 0.3. Most displays hide this by rounding, but comparisons and long chains expose it.| Key | Meaning |
|---|---|
| DEG / RAD / GRAD | Angle unit — 360, 2π or 400 to a full turn |
| SHIFT / 2nd / INV | Access the second function printed above a key |
| M+ / M− / MR / MC | Add to, subtract from, recall and clear memory |
| ANS | The previous answer — the safe way to chain calculations |
| EXP / EE / ×10ₓ | Scientific notation entry — not the same as the power key |
| FIX / SCI / NORM | Display format: fixed decimals, scientific, or normal |
| STO / RCL | Store to and recall from a named variable |
Almost certainly the angle mode. sin(30) is 0.5 in degrees but −0.988 in radians, because in radian mode 30 means 30 radians. Look for DEG or RAD on the display and switch before trusting any trigonometric result.
Both describe the same rule. Multiplication and division share one priority and are done left to right, as do addition and subtraction. The mnemonics mislead by listing them in a fixed order that does not exist.
There is no universally agreed answer. Most calculators return 9, treating the division and the implicit multiplication as equal priority left to right, while some scientific models and many physics conventions return 1 by binding juxtaposition tighter. Write explicit brackets instead.
log is base 10 and ln is base e, approximately 2.71828. Confusingly, in most programming languages the function named log is the natural logarithm, so check which convention your tool follows.
Because binary floating point cannot represent 0.1 or 0.2 exactly, so their sum is very slightly off. Calculators usually round the display to hide it, but the discrepancy is real and shows up in comparisons and long calculation chains.
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