分析:綜合幾道題,發(fā)現(xiàn)運(yùn)用乘法的分配律,加法的交換律,能使計(jì)算簡便.
解答:解:2003×2003+2004×2004-2003×2004-2002×2003,
=2003×2003-2002×2003+2004×2004-2003×2004,
=2003×(2003-2002)+2004×(2004-2003),
=2003+2004,
=4007;
103.2+102.8+103.3+102.9+103.1+102.6,
=103×6+(0.2-0.2+0.3-0.1+0.1-0.4),
=618-0.1,
=617.9;
38.06×98-161.2×4.9,
=38.06×98-8.06×98,
=(38.06-8.06)×98,
=30×98,
=2940;
62.4×4.8÷3.12÷8,
=62.4÷3.12×4.8÷8,
=20×0.6,
=12;
27.3÷36+2.05÷3.6+206÷360,
=27.3÷36+2.05÷3.6+206÷360
=273÷360+205÷360+206÷360
=(273+205+206)÷360
=684÷360
=1.9.
點(diǎn)評:解答此題的關(guān)鍵是,根據(jù)所給數(shù)的特點(diǎn),找出能夠使運(yùn)算簡便的方法,即可解答.