Ответ:

а)

  1. \(321-18=303\).
  2. \(27\,609-7\,609=20\,000\).
  3. \(303\cdot304\cdot20\,000:4\,000=303\cdot304\cdot5\).
  4. \(303\cdot304=92\,112\).
  5. \(92\,112\cdot5=460\,560\).

б)

  1. \(627+163=790\).
  2. \(937-637=300\).
  3. \(63\,000\cdot790\cdot300:90\,000=\frac{63\,000}{90\,000}\cdot790\cdot300\).
  4. \(0.7\cdot790\cdot300=165\,900\).

Ответ: а) 460 560; б) 165 900.