28140:70=(28000:70)+(140:70)=400+2=402
21800:20=(20000:20)+(1800:20)=1000+900=1900
32400:30=(30000:30)+(2400:30)=1000+80=1080
424900:700=(420000:700)+(4900:700)=600+7=607
364500:900=(360000:900)+(4500:900)=400+5=405
342 000:300=(300000:300)+(42000:300)=1000+1140=1140
336 000:800=(320000:800)+(16000:800)=400+20=420