(2)
=(3)
=(4)
=(5)
=(6)
=解:(1)3450-450÷25×18,=3450-18×18,
=3450-324,
=3126;
(2)
,=
÷6
,=
;(3)
,=7.2+10.4,
=17.6;
(4)
,=(
-
)÷6+4
,=
÷6+4
,=
+4
,=
;(5)

=
-(
-
)×
,=
-
×
,=
-
,=
;(6)
,=1+
+1+
+1+
+1+
+1+
,=5+(
+
+
+
+
),=5+
×(1-
+
-
+
-
+
-
+
-
),=5+
×(1-
),=5+
×
,=5+
,=5
;分析:(1)先算除法,再算乘法,最后算减法,
(2)按照从左到右的顺序计算;
(3)先算乘除法,再算加法;
(4)先算括号里,再算括号外的;
(5)先算括号里,再算乘除法,最后算减法;
(6)把算式化成1+
+1+
+1+
+1+
+1+
,在进行计算.点评:考查了整数、小数、分数的四则混合运算顺序及灵活运用运算定律进行简算.