187 + 75 = 262
$\snippet{name: op_column, sign: '+', x: '187', y: '75', z: '262'}$
 
850 − 86 = 764
$\snippet{name: op_column, sign: '-', x: '850', y: '86', z: '764'}$
 
238 + 93 = 331
$\snippet{name: op_column, sign: '+', x: '238', y: '93', z: '331'}$
 
540 + 30 = 570
 
540 + 300 = 840
 
540 + 330 = 870
 
17 * 4 : 2 = (10 + 7) * 4 : 2 = (10 * 4 + 7 * 4) : 2 = (40 + 28) : 2 = 68 : 2 = (60 + 8) : 2 = 60 : 2 + 8 : 2 = 30 + 4 = 34
 
28 * 3 : 4 = (20 + 8) * 3 : 4 = (20 * 3 + 8 * 3) : 4 = (60 + 24) : 4 = 84 : 4 = (80 + 4) : 4 = 80 : 4 + 4 : 4 = 20 + 1 = 21
 
18 * 5 : 3 = (10 + 8) * 5 : 3 = (10 * 5 + 8 * 5) : 3 = (50 + 40) : 3 = 90 : 3 = 30
 
42 : 14 * 26 = 3 * 26 = 3 * (20 + 6) = 3 * 20 + 3 * 6 = 60 + 18 = 78
 
60 : 12 * 14 = 5 * 14 = 5 * (10 + 4) = 5 * 10 + 5 * 4 = 50 + 20 = 70
 
90 : 15 * 13 = 6 * 13 = 6 * (10 + 3) = 6 * 10 + 6 * 3 = 60 + 18 = 78