Can't I Calculate It Directly?

$\large{\begin{array}{cccccccc} &0 .& 1 & 2& 3 & 1&2& 3 & 1&\ldots\\ +&0. & 0 & 1& 2 & 3&1& 2 & 3&\ldots\\ \hline \phantom0\\ \hline \end{array}}$

The above shows an incomplete columnar addition of the two fractions $\dfrac{123}{999}$ and $\dfrac{123}{9990}$ when written in decimal representation.

What is the value of $12\times10101 + 123\times1001$ ?