Calculator
How to Use a Scientific Calculator
Updated October 2, 2026
Most wrong answers come from picking the wrong key, not from bad maths. Use the right function, watch your brackets, and check the mode (DEG or RAD) before you trust a trig result.
How to use CalcSolver in 3 steps
- Type your sum — use the keypad or your keyboard.
- Press Enter — the answer shows right under your sum.
- Press Esc to clear — start again with a blank display.
Keyboard keys that work: digits, + − * /, Enter, Backspace and Esc.
Keyboard shortcuts
| Do this | Press | Example | Result |
|---|---|---|---|
| Get the answer | Enter or = | 15 + 85 ÷ 5 | 32 |
| Clear the display | Esc | — | 0 |
| Delete the last character | Backspace | — | — |
| Raise to a power | ^ | 2 ^ 8 | 256 |
| Brackets | ( ) | (4 + 6) × 3 | 30 |
Which key do I use?
| Key | Use it for | Example |
|---|---|---|
| log | Base 10 | log(1000) = 3 |
| ln | Base e | ln(100) = 4.6052 |
| log(x) ÷ log(b) | Any base | log base 2 of 8 = log(8) ÷ log(2) = 3 |
| x! | Factorials | 5! = 120 |
| nCr | Combinations | nCr(10, 3) = 120 |
| nPr | Permutations | nPr(5, 2) = 20 |
| sqrt( ) | Square root of what's inside the brackets | sqrt(9 + 16) = 5 |
Two notes that save marks
Your calculator may only have log and ln, so use the any-base trick in the table for base 2. And 170! is the largest factorial that fits. It's about 7.26 × 10^306. Type 171! and you'll see Infinity.
Watch the brackets on roots: sqrt(9 + 16) = 5, but sqrt(9) + 16 = 19.
Order of operations
CalcSolver follows the standard order: brackets first, then powers, then × and ÷, then + and −. So 8 + 2 × 5 gives 18, not 50.
How the percent key works
The % key works on the number next to it. Typing 200 + 15% gives 200.15 here, because 15% becomes 0.15. If you want 15% added to 200, type 200 × 1.15 and you'll get 230.
Postfix % divides by 100 (e.g. 200 + 15% = 200.15). For 15% more than 200, use 200 × 1.15.
Five input mistakes (and the fix)
| What you meant | What you typed | What you got | Fix |
|---|---|---|---|
| sin of 30 degrees | sin(30) in RAD mode | −0.988 | Switch to DEG |
| log base 10 of 100 | ln(100) | 4.6052 | Use log, which gives 2 |
| 1 ÷ (2 + 3) | 1 ÷ 2 + 3 | 3.5 | Add brackets, which gives 0.2 |
| (8 + 2) × 5 | 8 + 2 × 5 | 18 | Add brackets, which gives 50 |
| sqrt of (9 + 16) | sqrt(9) + 16 | 19 | Put everything inside, which gives 5 |
One more: −2^2 is −4, because the power happens first. But (−2)^2 is 4.
Need the angle-mode test? See Degrees vs radians explained. Wondering why sin(180) looks tiny? Read Why calculators show tiny errors.