599996+49997+3998+299+31
12个回答

599996+49997+3998+299+31

=599996+49997+3998+299+(4+3+2+1+20+1)

=(599996+4)+(49997+3)+(3998+2)+(299+1)+20+1

=600000+50000+4000+300+20+1

=654321

有不懂的问我吧.