27+55+84+45+73
=(27+73)+(55+45)+84
=100+100+84
=284
9+261+51+39+40
=(261+39)+(9+51+40)
=300+100
=400
43+164+57-42
=(43+57)+(164-42)
=100+122
=222
173+98+102-64
=(173-64)+(98+102)
=109+200
=309
347-178+653
=(347+653)-178
=1000-178
=822
868+387-187+132
=(868+132)+(387-187)
=1000+200
=1200