+, -, ×, /: Basic arithmetic operations
CE: Clear current entry
C: Clear all
←: Backspace
sin, cos, tan: Trig functions (input in radians)
asin, acos, atan: Inverse trig functions (output in radians)
log: Base-10 logarithm
ln: Natural logarithm
x², x³: Square and cube
n!: Factorial
MC: Clear memory (sets to 0)
MR: Recall memory value to display
MS: Store current display value in memory
M+: Add display value to memory
M-: Subtract display value from memory
π: Pi (≈3.14159)
NA: Avogadro's number (≈6.022e23)
kT ln 2: Landauer limit (≈9.57e-24 J/K at 300K)
ℏ: Reduced Planck constant (≈1.054e-34 J⋅s)
φ: Golden ratio (≈1.618)