Public index · Mathematics
6 × 9 in base 13
42₁₃
Calculated
The arithmetic joke that 6 × 9 = 42 in base 13
6 × 9 = 54₁₀ = 4×13 + 2 = 42 in base 13. The arithmetic holds. Adams denied it as his origin. A frame, not a transit.
What it supports
A true change-of-base identity, later attached to Hitchhiker as fan mathematics.
What it does not
Adams, 3 Nov 1993: binary representations, base thirteen, Tibetan monks are all complete nonsense. Keep the identity; do not overwrite the author.
Calculation
6×9 = 54; 54 = 4×13 + 2 → 42₁₃
Positional notation, base 13
ExactnessDerived mathematics
Form42
Unitbase-13
Strengthhard