140527*7-8037*60=501469
1)140527*7=983689
2)8037*60=482220
3)983689-482220=501469
387304:4+3460800:60=673626
1)387304:4=96826
2)3460800:6=576800
2)96826+576800=673626
500*3700-781140:2=1459430
1)500*3700=1850000
2)781140:2=390570
3)1850000-390570=1459430