①3654879<3654897;
②27万=270000,所以26900100000>27万;
③12<30,所以480÷12>480÷30;
④18×500=18×50×10,50×180=50×18×10,所以18×500=50×180;
故答案为:<,>,>,=.
①3654879<3654897;
②27万=270000,所以26900100000>27万;
③12<30,所以480÷12>480÷30;
④18×500=18×50×10,50×180=50×18×10,所以18×500=50×180;
故答案为:<,>,>,=.