\documentclass{standalone}
\usepackage{times}
\usepackage{array}
\usepackage{amsmath,amssymb}
\usepackage{tikz}
\usetikzlibrary{arrows}
\usetikzlibrary{shapes}
\usetikzlibrary{backgrounds}
\usetikzlibrary{patterns}
\usetikzlibrary{positioning}

\newcommand{\cancel}[1]{%
	\tikz[baseline=(tocancel.base)]{
		\node[inner sep=0pt,outer sep=0pt] (tocancel) {#1};
		\draw[red,thick,line cap=round] (tocancel.south west) -- (tocancel.north east);
	}%
}%

\begin{document}
$
\begin{array}{@{}r@{\,\,}c@{\,\,}l@{}}
	\displaystyle\log(1)+\log(2)+\log(3)&=&\displaystyle\log(1+2+3)\\[1ex]
	%230-220\cdot0.5&=5!\\
	\displaystyle\frac{1\cancel{63}}{\cancel{3}2\cancel{6}}&=&\displaystyle\frac{1}{2}~.
\end{array}
$
\end{document}
