问题 解答题
用简便方法计算(要写出简算过程)
①475-198
②0.7+3.9+4.3+6.1
③(
1
3
+
2
5
)×15.
答案

①475-198,

=475-(200-2),

=475-200+2,

=275+2,

=277;

②0.7+3.9+4.3+6.1,

=(0.7+4.3)+(3.9+6.1),

=5+10,

=15;

③(

1
3
+
2
5
)×15,

=

1
3
×15+
2
5
×15,

=5+6,

=11.

问答题
单项选择题