400 − 208;
504 − 397;
109 * 6;
205 * 4;
168 * 4;
168 : 4;
648 : 6;
927 : 9.

400 − 208; 504 − 397; 109 * 6; 205 * 4; 168 * 4; 168 : 4; 648 : 6; 927 : 9.

\begin{array}{r} \begin{array}{r} - \end{array} \begin{array}{r} 400 \\ 208 \end{array} \\ \begin{array}{r} 192 \end{array} \end{array}

\begin{array}{r} \begin{array}{r} - \end{array} \begin{array}{r} 504 \\ 397 \end{array} \\ \begin{array}{r} 107 \end{array} \end{array}

\begin{array}{r} \times \underline{\begin{array}{r} 109 \\ 6 \end{array}} \\ 654 \end{array}

\begin{array}{r} \times \underline{\begin{array}{r} 205 \\ 4 \end{array}} \\ 820 \end{array}

\begin{array}{r} \times \underline{\begin{array}{r} 168 \\ 4 \end{array}} \\ 672 \end{array}

\begin{matrix} \begin{array}{l} \underline{} 168 \\ \underline{16} \\ \underline{} 8 \\ \underline{8} \\ 0 \end{array} & \begin{array}{l} 4 \\ \bar{42} \end{array} \end{matrix}

\begin{matrix} \begin{array}{l} \underline{} 648 \\ \underline{6} \\ \underline{} 4 \\ \underline{0} \\ \underline{} 48 \\ \underline{48} \\ 0 \end{array} & \begin{array}{l} 6 \\ \bar{108} \end{array} \end{matrix}

\begin{matrix} \begin{array}{l} \underline{} 927 \\ \underline{9} \\ \underline{} 2 \\ \underline{0} \\ \underline{} 27 \\ \underline{27} \\ 0 \end{array} & \begin{array}{l} 9 \\ \bar{103} \end{array} \end{matrix}