Ответ:

  1. \(0.6+0.4=1\);
  2. \(0.6+0.04=0.64\);
  3. \(0.6-0.4=0.2\);
  4. \(0.6-0.04=0.56\);
  5. \(0.6\cdot4=2.4\);
  6. \(0.6\cdot0.4=0.24\);
  7. \(6:4=1.5\);
  8. \(0.6:4=0.15\).