简便计算.1.123+13.78+0.877 202.02-162.2-
1个回答

解题思路:(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.

(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:

本题考点: 运算定律与简便运算.

考点点评: 完成本题要注意分析式中数据,运用合适的简便方法计算.