Номер 118

1000+ 4000 = 5000
3000 - 3000 = 0
645 - 45 * 3 = 645-135 = 510
125 + 75: 3 = 125 + (60+ 15) : 3 = 125 + 60 : 3 + 15 : 3 = 125 + 20 + 5 = 150