2400 * 30 = 72000
 
450 * 600 = 270000
 
80 * 926 = 74080
$\snippet{name: op_column, sign: '×', x: '926  ', y: '80', z: '74080 '}$
 
200 * 75 = 15000
 
190 * 300 + 929 * 40 = 57000 + 37160 = 94160
$\snippet{name: op_column, sign: '×', x: '929  ', y: '40', z: '37160 '}$
$\snippet{name: op_column, sign: '+', x: '57000', y: '37160', z: '94160'}$
 
720 * 100 − 28142 : 2 = 72000 − 14071 = 57929
$\snippet{name: long_division, x: 28142, y: 2}$
$\snippet{name: op_column, sign: '-', x: '72000', y: '14071', z: '57929'}$