Calculator skills
Order of Operations: Avoid These Calculator Pitfalls
Updated October 2, 2026
Published by SolveCalc (Operator of solvecalc.live)
Calculators follow a fixed order. If what you type skips brackets the machine still needs, you get a different answer than the one on your worksheet—even when every digit looks right.
A practical order
- Parentheses / brackets
- Exponents (powers and roots)
- Multiplication and division, left to right
- Addition and subtraction, left to right
Unary minus still interacts with powers: −2^2 is usually treated as −(2²) = −4, while (−2)^2 is 4.
What you meant vs what you typed
| You meant | You typed | You got | Fix |
|---|---|---|---|
| sin of 30° | sin(30) in RAD | ≈ −0.988 | Switch to DEG |
| log₁₀(100) | ln(100) | ≈ 4.605 | Use log → 2 |
| 1 ÷ (2 + 3) | 1 ÷ 2 + 3 | 3.5 | Add brackets → 0.2 |
| (8 + 2) × 5 | 8 + 2 × 5 | 18 | Add brackets → 50 |
| √(9 + 16) | sqrt(9) + 16 | 19 | Put all inside → 5 |
A 10-second check
- Estimate. For 48 × 19.7, think 50 × 20 = 1,000. The real answer is 945.6, so it is in the right ballpark.
- Undo it. Divide your product by one factor; you should recover the other.
- Check the range. sin and cos stay between −1 and 1. A result like 1.4 means the mode or expression is wrong.
Practice
Try the rows above on the scientific calculator. For mode mistakes, read Degrees vs radians explained. For key choices (log vs ln, nCr, factorials), see How to use a scientific calculator.