分析:(1)运用加法结合律简算;
(2)运用减法的性质简算;
(3)直接计算即可,注意小数点对齐;
(4)运用减法的性质简算.
解答:解:(1)1.123+13.78+0.877
=(1.123+0.877)+13.78
=2+13.78
=15.78;
(2)202.02-162.2-37.8
=202.02-(162.2+37.8)
=202.02-200
=2.02;
(3)48+9.9=57.9;
(4)198.81-(98.81+5.4)
=198.81-98.81-5.4
=(198.81-98.81)-5.4
=100-5.4
=94.6.
点评:完成本题要注意分析式中数据,运用合适的简便方法计算.