[Tex/LaTex] writing inside a ball in a itemize/enumerate in Beamer

Question

I am doing a Beamer and I don't know how to put something like that:

\begin{enumerate}
\item item1
\end{enumerate}

\begin{itemize}
\item[1'] % I want that the 1' appears inside a ball.
\end{itemize}

\begin{enumerate}\setcounter{enumi}{1}
\item item2
\item item3
\end{enumerate}

Answer 1

The easy way for automatic numeration: use an appropriate theme in the preamble:

\usetheme{JuanLesPins} % or Madrid, or ...

The hard way for the same: remember to write

\setbeamertemplate{items}[ball]

(...and set more things to have an attractive presentation).

For custom items a solution could be tikz macro that can look almost as the default numbered items, but in long items the ball become enormous. The same as rounded boxes are more elegant in this case. There are other possible decorations without managing directly tkiz. For example, the menukeys, or without extra packages, with \fbox or \textcircle (but the last one do not allow much more that one digit). With the pifont package it is possible print one digit in filled circle, but anything extra must be outside. A comparison of these methods is made in this MWE:

\documentclass{beamer}
\usetheme{Madrid}
\setbeamercolor{structure}{fg=purple}  
\usepackage{menukeys} % for \keys
\usepackage{pifont}   % for \ding
\usepackage{tikz}

% tkiz ball item
\newcommand*\circled[1]{\tikz[baseline=(char.base)]{
            \node[circle,ball color=purple, shade, 
 color=white,inner sep=1.2pt] (char) {\tiny #1};}}

% tkiz rounded item
\newcommand*\rounded[1]{\tikz[baseline=(char.base)]{
            \node[draw=none,ball color=purple, shade, 
 color=white, rounded corners=3.5pt, inner sep=2.5pt] (char) {\scriptsize #1};}}


\begin{document}
\begin{frame}{}

 \begin{enumerate}
    \item Default item  
    \item[\circled{2}] Item with {\tt tikz} ball 
    (not so smooth)     
    \item[\circled{3'}] With {\tt tikz} ball (bigger)
    \item[\circled{3''b}] With {\tt tikz} ball (really big) 
    \item[\rounded{4}] With {\tt tikz} roundex box      
    \item[\rounded{4'}] With {\tt tikz} rounded box     
    \item[\rounded{4''b}] With {\tt tikz} rounded box 
    \item[\textcircled{\scriptsize{5}}'] With\textbackslash{\tt texcircled} item (not expandable)
    \item[\large\ding{187}'] With {\tt pifont} (\textbackslash{ding}\{\})   
    \item[\small\keys{7'}] With {\tt menukey}   
    \item[\small\fbox{8'}] With \textbackslash{\tt fbox}    
    \end{enumerate}

\end{frame}

\end{document}