$724 \overset{2}{-} (309 \overset{1}{-} 156) \overset{3}{+} 329 = 900$
1) $\snippet{name: op_column, sign: '-', x: '309', y: '156', z: '153'}$;
2) $\snippet{name: op_column, sign: '-', x: '724', y: '153', z: '571'}$;
3) $\snippet{name: op_column, sign: '+', x: '571', y: '329', z: '900'}$.
 
$430 \overset{3}{-} (87 \overset{1}{+} 218 \overset{2}{-} 132) = 257$
1) $\snippet{name: op_column, sign: '+', x: '87', y: '218', z: '305'}$;
2) $\snippet{name: op_column, sign: '-', x: '305', y: '132', z: '173'}$;
3) $\snippet{name: op_column, sign: '-', x: '430', y: '173', z: '257'}$.