# Centering displayed math within enumerate environment [duplicate]

This is my first post so apologies if there are any community rules that I overlooked.

If I write something in displayed math within an enumerate environment this is not centered with respect to the enumerate environment but with respect to the whole text. The following image shows what I mean:

The code for reproducing the above is as follows. I use the geometry, enumitem and parskip packages but similar situation occurs without them as well. I include them in the code since I would like a solution compatible with those packages.

\documentclass[a4paper,12pt]{amsart}
\usepackage[margin=1in]{geometry}
\usepackage{enumitem}
\usepackage{parskip}

\begin{document}

\begin{enumerate}
\item This is the first item. I am just writing some nonsense to fill up the line. Now for a long displayed formula
$1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1$
\end{enumerate}
This is some text following the enumerate environment to indicate that the formula is aligning with respect to this text rather than within the environment.
\end{document}


I find the above rather ugly and I prefer instead the following image:

\hspace{0.5\labelwidth} \hspace{0.5\labelsep} \hspace{0.5\leftmargin}

inside the displayed math.

My two questions are:

1. Am I wrong in preferring the second image to the first?
2. What is the best way of obtaining the second image?

See, if the following solution is acceptable:

By inserting equation into minipage:

\documentclass[a4paper,12pt]{amsart}
\usepackage[margin=1in]{geometry}
\usepackage{enumitem}
\usepackage{parskip}

\begin{document}

\begin{enumerate}
\item This is the first item. I am just writing some nonsense to fill up the line. Now for a long displayed formula\par\vspace{-0.8\baselineskip}
\begin{minipage}{\linewidth}
$1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1$
\end{minipage}
\end{enumerate}
This is some text following the enumerate environment to indicate that the formula is aligning with respect to this text rather than within the environment.
\end{document}