The square of the number 104 is [[1]].

The calculation of the square of 104 can be simplified by breaking the number into 100 and 4.

$\begin{array}{rcl}{\left(104\right)}^2& =& {\left(100+4\right)}^2\\ & =& {100}^2+4^2+2\times 100\times 4\\ & =& 10000+16+800\\ & =& 10816\end{array}$