MHB 57^(th) digit in decimal expansion

[juantheron]

Calculation of $57^{th}$ digit in the decimal expansion of $\displaystyle \frac{1}{57}$

 

[I like Serena]

Calculation of $57^{th}$ digit in the decimal expansion of $\displaystyle \frac{1}{57}$

If you are allowed mod calculation and Euler's phi function, you can use >>this<<.
It gives you the period of the decimal expansion, meaning it suffices to calculate a decimal that comes much earlier in the expansion.