Question

用简便方法计算．

2003×2003+2004×2004-2003×2004-2002×2003．	62.4×4.8÷3.12÷8．
103.2+102.8+103.3+102.9+103.1+102.6．	27.3÷36+2.05÷3.6+206÷360．
38.06×98-161.2×4.9．

Answer 1

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．