(1)2.18+3.7+0.82+6.3
=(2.18+0.82)+(3.7+6.3),
=3+10,
=13;
(2)(620+380)÷50×4
=1000÷50×4,
=20×4,
=80;
(3)528×58+472×58
=(528+472)×58,
=1000×58,
=58000;
(4)125×96×8
=125×8×96,
=1000×96,
=96000;
(5)9.5+4.85-8.16
=14.35-8.16,
=6.19;
(6)51.27-8.66-1.34
=51.27-(8.66+1.34),
=51.27-10,
=41.27.