Ответ:\(999+1=1000\).\(900-1=899\).\(700+80+9=789\).\(347-7-40=340-40=300\).\(570+30-330=600-330=270\).\(950+50-660=1000-660=340\).Ответ: 1000; 899; 789; 300; 270; 340.