3-
×
+
0.9-(0.15+0.35÷
)7.25-3
+3.75-6
(2-
×
)÷(
+
)①解:3-
×
+
=3-
×
+
=3-
+
=2
+
=3
;②解:0.9-(0.15+0.35÷
)=0.9-(0.15+
÷
)=0.9-(0.15+
×
)=0.9-(0.15+0.49)
=0.9-0.64
=0.26;
③解:7.25-3
+3.75-6
=(7.25+3.75)-(3
+6
)=11-10
=1;
④解:(2-
×
)÷(
+
)=(2-
)÷
=
×
=4.
分析:①④按四则混合运算的顺序运算计算;
②能使用简便算法的使用简便算法计算;
③分数和小数之间的互化要利于计算.
点评:注意别进入简便算法的陷阱,如①,只能按顺序计算.