Answer
$6.23\times10^{2}$
Work Step by Step
Using $a\times10^n$, where $1\le a\le9,$ and $n$ is an integer, the scientific notation of the given expression, $
623
,$ is
\begin{array}{l}\require{cancel}
6.23
\times100
\\\\=
6.23\times10^{2}
.\end{array}