504 − x = 102
x = 504 − 102
x = 402
Проверка:
504 − 402 = 102
102 = 102
 
Вычисления:
$\snippet{name: op_column, sign: '-', x: '504', y: '102', z: '402'}$
 
$\snippet{name: op_column, sign: '-', x: '504', y: '402', z: '102'}$
 
376 + x = 400
x = 400 − 376
x = 24
Проверка:
376 + 24 = 400
400 = 400
 
Вычисления:
$\snippet{name: op_column, sign: '-', x: '400', y: '376', z: '24'}$
 
$\snippet{name: op_column, sign: '+', x: '376', y: '24', z: '400'}$
 
x − 229 = 78
x = 78 + 229
x = 307
Проверка:
307 − 229 = 78
78 = 78
 
Вычисления:
$\snippet{name: op_column, sign: '+', x: '78', y: '229', z: '307'}$
 
$\snippet{name: op_column, sign: '-', x: '307', y: '229', z: '78'}$
 
x + 345 = 812
x = 812 − 345
x = 467
Проверка:
467 + 345 = 812
812 = 812
 
Вычисления:
$\snippet{name: op_column, sign: '-', x: '812', y: '345', z: '467'}$
 
$\snippet{name: op_column, sign: '+', x: '467', y: '345', z: '812'}$
 
x * 40 = 120
x = 120 : 40 = 12 : 4
x = 3
Проверка:
3 * 40 = 120
3 * 4 * 10 = 120
12 * 10 = 120
120 = 120
 
x : 5 = 68
x = 68 * 5 = (60 + 8) * 5 = 60 * 5 + 8 * 5 = 300 + 40
x = 340
Проверка:
340 : 5 = 68
(300 + 40) : 5 = 68
300 : 5 + 40 : 5 = 68
60 + 8 = 68
68 = 68
 
450 : x = 9
x = 450 : 9 = 45 д : 9 = 5 д
x = 50
Проверка:
450 : 50 = 9
45 : 5 = 9
9 = 9
 
36 * x = 720
x = 720 : 36 = 72 д : 36 = 2 д
x = 20
Проверка:
36 * 20 = 720
36 * 2 * 10 = 720
(30 + 6) * 2 * 10 = 720
(30 * 2 + 6 * 2) * 10 = 720
(60 + 12) * 10 = 720
72 * 10 = 720
720 = 720