Ответ:

  1. \(356 + 300 = 656\)
  2. \(356 + 30 = 386\)
  3. \(356 + 3 = 359\)
  4. \(748 - 200 = 548\)
  5. \(748 - 20 = 728\)
  6. \(748 - 2 = 746\)
  7. \(235 + 4 = 239\)
  8. \(235 + 400 = 635\)
  9. \(235 + 40 = 275\)
  10. \(897 - 50 = 847\)
  11. \(897 - 5 = 892\)
  12. \(897 - 500 = 397\)

Ответ: 656; 386; 359; 548; 728; 746; 239; 635; 275; 847; 892; 397.