$750 \overset{2}{-} (203 \overset{1}{+} 49) = 750 - 252 = 498$
1) $\snippet{name: op_column, sign: '+', x: '203', y: '49', z: '252'}$;
2) $\snippet{name: op_column, sign: '-', x: '750', y: '252', z: '498'}$.

$(512 \overset{1}{-} 184) \overset{3}{-} 93 \overset{4}{+} (106 \overset{2}{-} 67) = 328 - 93 + 39 = 274$
1) $\snippet{name: op_column, sign: '-', x: '512', y: '184', z: '328'}$;
2) $\snippet{name: op_column, sign: '-', x: '106', y: '67', z: '39'}$;
3) $\snippet{name: op_column, sign: '-', x: '328', y: '93', z: '235'}$;
4) $\snippet{name: op_column, sign: '+', x: '235', y: '39', z: '274'}$.