How to Use a Scientific Calculator: Trig, Logs, Powers & More

A scientific calculator is essential for anything beyond basic arithmetic — from high school maths to engineering. Here’s how to use every major function.

BODMAS / PEMDAS order of operations

Scientific calculators follow strict operator precedence:

1. Brackets (Parentheses)
2. Orders (Exponents / Powers)
3. Division and Multiplication (left to right)
4. Addition and Subtraction (left to right)

Example: 3 + 4 × 2 = 3 + 8 = 11 (not 14)

Trigonometric functions

Degrees vs Radians

Always check your angle mode! Common mistake: calculating sin(90) in RAD mode gives 0.894 (wrong) instead of 1.0 (correct in DEG mode).

• DEG: Angles in degrees (0–360°). Use for most real-world problems.
• RAD: Angles in radians (0–2π). Use for calculus and physics.
• Conversion: Radians = Degrees × π/180

Key trig values to know

Angle	sin	cos	tan
0°	0	1	0
30°	0.5	0.866	0.577
45°	0.707	0.707	1
60°	0.866	0.5	1.732
90°	1	0	undefined

Logarithms

• log(x) = log base 10. “What power of 10 gives x?” log(100) = 2
• ln(x) = natural log (base e ≈ 2.718). Used in calculus, growth/decay.
• Relationship: ln(x) = log(x) × 2.303

Powers and roots

• x² — square
• x³ — cube
• xⁿ — any power
• √x — square root
• ⁿ√x — nth root (same as x^(1/n))

Memory functions

• M+ — Add current display to memory
• M- — Subtract from memory
• MR — Recall (display) stored value
• MC — Clear memory

Useful for multi-step problems where you need to store intermediate results.

Common mistakes

1. Wrong angle mode — #1 cause of wrong trig answers
2. Missing brackets — sin(30+45) ≠ sin 30 + 45
3. Division ambiguity — 6/2(1+2): always use explicit brackets
4. Negative signs — (-3)² = 9, but -3² = -9 on most calculators

Use our Scientific Calculator — full-featured, works on mobile, supports keyboard input, and shows calculation history.