Ответ:

  1. \(570\cdot902\approx570\cdot900=513\,000\).
  2. \(625\cdot127\approx625\cdot130=81\,250\).
  3. \(315514:361\approx315000:360\approx875\).
  4. \(743700:925\approx744000:900\approx827\).
  5. \(3509\cdot9070\approx3500\cdot9000=31\,500\,000\).
  6. \(802494:386\approx802000:400\approx2005\).

Ответ: примерно 513 000; 81 250; 875; 827; 31 500 000; 2 005.