+12×175%)÷
(2)0.35÷0.125÷64÷0.5÷0.25
(3)1.25×98+12
×
+1
(4)3
×2345+555÷
+654.3×36(5)
+
-
+
-
+
-
(6)
+
+…
=2008.解:(1)(28×
+12×175%)÷
,=(28×
+12×175%)×
,=28×
×
+12×175%×
,=
+8,=26
;(2)0.35÷0.125÷64÷0.5÷0.25,
=0.35÷(0.125×64×0.5×0.25),
=0.35÷(0.125×8×8×0.5×0.25),
=0.35÷[(0.125×8)×(0.5×0.25×8)],
=0.35÷[1×1],
=0.35÷1,
=0.35;
(3)1.25×98+12
×
+1
,=1.25×98+12.5×0.1+1.25,
=1.25×98+1.25×1+1.25,
=1.25×(98+1+1),
=1.25×100,
=125;
(4)3
×2345+555÷
+654.3×36,=3.6×2345+555÷
+6543×3.6,=3.6×2345+6543×3.6+555÷
,=3.6×(2345+6543)+555×
,=3.6×8888+5683.2,
=37680;
(5)
+
-
+
-
+
-
,=1-
+
+
-
-
+
+
-
-
+
+
-
-
,=1-
,=
;(6)
+
+…
=2008,x-
+
-
+…+
-
=2008,x-
=2008,
x=2008,
x÷
=2008÷
,x=2009.
分析:(1)把除以
化成乘以
,再运用乘法分配律进行简算;(2)运用除法的运算定律进行简算;
(3)运用乘法分配律进行简算;
(4)把654.3×36化成6543×3.6,运用乘法分配律进行简算;
(5)把算式
+
-
+
-
+
-
化成1-
+
+
-
-
+
+
-
-
+
+
-
-
进行简算;(6)把
+
+…
=2008化成x-
+
-
+…+
-
=2008,再解方程即可.点评:运算定律是常用的简便运算的方法,要熟练掌握,灵活运用.