考點:小數(shù)四則混合運算,分?jǐn)?shù)的四則混合運算
專題:運算順序及法則
分析:(1)根據(jù)加法交換律和結(jié)合律進行簡算;
(2)根據(jù)除法的性質(zhì)進行簡算;
(3)根據(jù)乘法交換律和結(jié)合律進行簡算;
(4)根據(jù)乘法分配律和乘法交換律進行簡算;
(5)根據(jù)加法交換律和結(jié)合律進行簡算;
(6)根據(jù)乘法分配律進行簡算;
(7)根據(jù)乘法分配律進行簡算;
(8)根據(jù)乘法分配律進行簡算;
(9)根據(jù)乘法分配律進行簡算;
(10)先算乘法,再算加法,最后算除法;
(11)中括號里面根據(jù)減法的性質(zhì)進行簡算,最后算除法;
(12)先算小括號里面的加法,再算除法,最后算括號外面的加法;
(13)根據(jù)乘法分配律進行簡算;
(14)先算加法,再算除法,最后算乘法.
解答:
解:(1)5.48-8.73+4.52-1.27
=(5.48+4.52)-(8.73+1.27)
=10-10
=0;
(2)9.7÷1.25÷0.8
=9.7÷(1.25×0.8)
=9.7÷1
=9.7;
(3)0.125×0.25×32
=0.125×0.25×(4×8)
=(0.125×8)×(0.25×4)
=1×1
=1;
(4)(6.3-6.3×0.9)÷6.3
=6.3×(1-0.9)÷6.3
=6.3×0.1÷6.3
=6.3÷6.3×0.1
=1×0.1
=0.1;
(5)
+
-(
-
)
=
+
-
+
=(
-
)+(
+
)
=0+1
=1;
(6)75×
=(76-1)×
=76×
-1×
=23-
=22
;
(7)2500÷
+2500×
=2500×
+2500×
=2500×(
+
)
=2500×2
=5000;
(8)9.25×9.9+92.5%
=0.925×99+0.925
=0.925×(99+1)
=0.925×100
=92.5;
(9)78×25%+
×23-0.25
=78×0.25+0.25×23-0.25
=(78+23-1)×0.25
=100×0.25
=25;
(10)
÷(
+
×
)
=
÷(
+
)
=
÷
=
;
(11)
÷[
-(
-
)]
=
÷[
-
+
]
=
÷[
+
-
]
=
÷[1-
]
=
÷
=
;
(12)(
+
)÷
+
=
÷
+
=
+
=
;
(13)12×(
+
-
)
=12×
+12×
-12×
=3+2-8
=5-8
=-3;
(14)
×[
÷(
+
)]
=
×[
÷
]
=
×
=
.
點評:考查了運算定律與簡便運算,四則混合運算.注意運算順序和運算法則,靈活運用所學(xué)的運算定律簡便計算.