Accurate to n Decimal Places/Examples/Pi to 4 Places

Example of Accurate to $n$ Decimal Places
The constant pi ($\pi$) expressed accurate to $4$ decimal places is:
 * $\pi \approx 3 \cdotp 1415$

Proof
We start with the decimal expansion of $\pi$:

and so $\pi$ expressed to the first $4$ decimal places is:
 * $3.1415$