400:(730+270):2= 2000:(567+433):2= (348+653)*5:500=

400:(730+270):2=1,25        2000:(567+433):2=0730+270=1000                      567+433=1000    

1000:2=2,5                           2000:1000=2

2,5:2=1,25                          2:2=0