Ответ:

  1. \(8\,000 : (25 \cdot 4) = 8\,000 : 100 = 80\).
  2. \(9\,000 : (300 : 3) = 9\,000 : 100 = 90\).
  3. \(832 - 328 - 247 = 504 - 247 = 257\).
  4. \(603 - (347 - 189) = 603 - 158 = 445\).
  5. \(903 - (178 + 359) : 3 = 903 - 537 : 3 = 903 - 179 = 724\).
  6. \(324 + (503 - 299) : 4 = 324 + 204 : 4 = 324 + 51 = 375\).

Ответ: 80; 90; 257; 445; 724; 375.