Definition:Pi/Decimal Expansion/Mistake

Source Work

1986: David Wells: Curious and Interesting Numbers:

The Dictionary

$3 \cdotp 14159 \, 26535 \, 89793 \, 23846 \, 26433 \, 83279 \, 50288 \, 41972 \ldots$

Mistake

$3 \cdotp 14159 \, 26535 \, 89793 \, 23846 \, 26433 \, 83279 \, 50288 \, 41972 \ldots$

The decimal expansion is actually $3 \cdotp 14159 \, 26535 \, 89793 \, 23846 \, 26433 \, 83279 \, 50288 \, 41971 \ldots$

The $41$st digit is a $6$.

While the value of $\pi$ is equal to $3 \cdotp 14159 \, 26535 \, 89793 \, 23846 \, 26433 \, 83279 \, 50288 \, 41972$ to $40$ decimal places, that does not mean the $40$th digit is a $2$.

As given here, the $40$th digit has been rounded up inappropriately.

This mistake has been corrected in David Wells: Curious and Interesting Numbers (2nd ed.).

Sources

• 1986: David Wells: Curious and Interesting Numbers ... (previous) ... (next): $3 \cdotp 14159 \, 26535 \, 89793 \, 23846 \, 26433 \, 83279 \, 50288 \, 41972 \ldots$