$126 \overset{2}{+} (403 \overset{1}{-} 76) \overset{3}{-} 259 = 126 + 327 - 259 = 453 - 259 = 194$
$\snippet{name: op_column, sign: '-', x: '403', y: '76', z: '327'}$
$\snippet{name: op_column, sign: '+', x: '126', y: '327', z: '453'}$
$\snippet{name: op_column, sign: '-', x: '453', y: '259', z: '194'}$
 
$900 \overset{3}{-} (54 \overset{1}{+} 317 \overset{2}{+} 485) = 900 - (371 + 485) = 900 - 856 = 44$
$\snippet{name: op_column, sign: '+', x: '54', y: '317', z: '371'}$
$\snippet{name: op_column, sign: '+', x: '371', y: '485', z: '856'}$
$\snippet{name: op_column, sign: '-', x: '900', y: '856', z: '44'}$