$\snippet{name: op_column, sign: '+', x: '68', y: '29', z: '97'}$
 
$\snippet{name: op_column, sign: '-', x: '72', y: '18', z: '54'}$
 
$\snippet{name: op_column, sign: '+', x: '47', y: '39', z: '86'}$
 
$\snippet{name: op_column, sign: '-', x: '96', y: '69', z: '27'}$