\documentclass{article}
\usepackage{tikz}
\usetikzlibrary{shapes.geometric, calc}
\newcommand\score[2]{%
\pgfmathsetmacro\pgfxa{#1 + 1}%
\tikzstyle{scorestars}=[star, star points=5, star point ratio=2.25, draw, inner sep=0.15em, anchor=outer point 3]%
\begin{tikzpicture}[baseline]
\foreach \i in {1, ..., #2} {
\pgfmathparse{\i<=#1 ? "yellow" : "gray"}
\edef\starcolor{\pgfmathresult}
\draw (\i*1em, 0) node[name=star\i, scorestars, fill=\starcolor] {};
}
\pgfmathparse{#1>int(#1) ? int(#1+1) : 0}
\let\partstar=\pgfmathresult
\ifnum\partstar>0
\pgfmathsetmacro\starpart{#1-(int(#1)}
\path [clip] ($(star\partstar.outer point 3)!(star\partstar.outer point 2)!(star\partstar.outer point 4)$) rectangle
($(star\partstar.outer point 2 |- star\partstar.outer point 1)!\starpart!(star\partstar.outer point 1 -| star\partstar.outer point 5)$);
\fill (\partstar*1em, 0) node[scorestars, fill=yellow] {};
\fi
\end{tikzpicture}%
}
\begin{document}
\score{0}{5} That's appalling!
\small\score{2}{5} A meagre result.
\Huge{\score{4.4}{5} Wooo!}
\end{document}