+, -, ×, /: Basic arithmetic operations
CE: Clear current entry
C: Clear all
←: Backspace
sin, cos, tan: Trigonometric functions
asin, acos, atan: Inverse trigonometric functions
log: Base-10 logarithm
ln: Natural logarithm
x², x³: Square and cube
n!: Factorial
MC: Clear memory
MR: Recall memory
MS: Store in memory
M+: Add to memory
M-: Subtract from memory
π: Pi (3.14159...) - Circle ratio
NA: Avogadro's number
kT ln 2: Landauer limit
ℏ: Reduced Planck constant
φ: Golden ratio