考點(diǎn):分?jǐn)?shù)的簡(jiǎn)便計(jì)算
專題:運(yùn)算定律及簡(jiǎn)算
分析:(1)把帶分?jǐn)?shù)拆成“整數(shù)+分?jǐn)?shù)”的形式,運(yùn)用乘法分配律簡(jiǎn)算.
(2)運(yùn)用乘法交換律與結(jié)合律簡(jiǎn)算.
(3)(5)(7)(10)運(yùn)用乘法分配律簡(jiǎn)算.
(4)先算除法,再?gòu)淖笸乙来斡?jì)算.
(6)先算括號(hào)內(nèi)的,再算括號(hào)外的.
(8)把帶分?jǐn)?shù)化為假分?jǐn)?shù),約分計(jì)算.
(9)把36看作35+1,運(yùn)用乘法分配律簡(jiǎn)算.
解答:
解:(1)25
×8
=(25+
)×8
=25×8+
×8
=200+3
=203
(2)
×(15×
)×
=(
×
)×(15×
)
=
×2
=
(3)
×101-
=
×(101-1)
=
×100
=70
(4)
×
÷
×
=
×(
÷
)×
=
×
=
(5)
×99+
=
×(99+1)
=
×100
=60
(6)(
+
)×
=
×
=
(7)
×
+
×
-
=(
+
-1)×
=
×
=
(8)3
×25
=
×25
=95
(9)36×
=(35+1)×
=35×
+
=34+
=34
(10)(
-
)×
=
×
-
×
=3-2
=1
點(diǎn)評(píng):仔細(xì)分析數(shù)據(jù),運(yùn)用合適的簡(jiǎn)便方法計(jì)算.