How to Use a Scientific Calculator
A scientific calculator goes far beyond basic arithmetic — it handles trigonometry, logarithms, exponents, roots, and factorials. Knowing the order in which to enter values and which mode (degrees vs radians) to use prevents the most common errors. This guide covers the key function groups with worked examples you can follow on any scientific calculator.
Last updated: March 31, 2026
The Formula
sin(θ), cos(θ), tan(θ) — trigonometric ratios log(x) = log base 10 of x ln(x) = natural logarithm (base e) x^y = x raised to the power y √x = square root of x n! = n × (n−1) × … × 1
Variable Definitions
| Symbol | Name | Description |
|---|---|---|
| θ | Angle | The input to trig functions — in degrees or radians depending on the mode set on the calculator |
| x | Operand | The number being operated on by log, ln, or √ |
| n | Integer | A whole number used in factorial calculations — n! is only defined for non-negative integers |
Step-by-Step Example
Evaluate: sin(30°) + log(1000) + 5! using a scientific calculator.
Given
Solution
- 1Set to DEG mode, compute sin(30):
sin(30°) = 0.5 - 2Compute log(1000):
log(1000) = 3 (because 10³ = 1000) - 3Compute 5!:
5! = 5 × 4 × 3 × 2 × 1 = 120 - 4Sum all three results:
0.5 + 3 + 120 = 123.5
The expression evaluates to 123.5.
Ready to calculate?
Use the free Scientific Calculator — instant results, no sign-up.
Common Mistakes to Avoid
Being in RAD mode when computing degree-based trig — always check the mode indicator before pressing sin/cos/tan.
Entering log(x) when you need ln(x) — log is base 10, ln is base e (≈ 2.718).
Pressing the exponent key in the wrong order — for x^y, enter x first, then ^ or y^x, then y.
Attempting n! for non-integers or very large n — most calculators cap factorial at n = 69 due to overflow.