این دستور را به قبل از \begin{document} اضافه کنید.
\makeatletter
\def\@makechapterhead#1{%
\vspace*{20\p@}%
{\parindent \z@ \normalfont
\ifnum \c@secnumdepth >\m@ne
\if@mainmatter
\Huge\bfseries {\scalebox{5}{\thechapter}}
\fi
\fi
\interlinepenalty\@M
\Huge \bfseries{ #1} %\par\nobreak
\vskip 40\p@
}}
\def\@makeschapterhead#1{%
\vspace*{50\p@}%
{\parindent \z@
\normalfont
\interlinepenalty\@M
\Huge \bfseries #1 \par\nobreak
\vskip 40\p@
}}
\makeatother
خروجی:
