7.8×101
÷
×64-1
×[
-(
-
)]
×0.53+75%×1.47 25×3.2×1.25
÷
.解:(1)7.8×101,
=7.8×(100+1),
=7.8×100+7.8×1,
=780+7.8,
=787.8;
(2)
÷
×64-1,=
×64-1,=41
-1,=40
;(3)
×[
-(
-
)],=
×[
-
+
],=
×[1-
],=
×
,=
;(4)
×0.53+75%×1.47,=0.75×0.53+0.75×1.47,
=0.75×(0.53+1.47),
=0.75×2,
=1.5;
(5)25×3.2×1.25,
=25×(4×0.8)×1.25,
=(25×4)×(0.8×1.25),
=100×1,
=100;
(6)
÷
,=(30+
)×
,=30×
+
×
,=28+
,=28
.分析:(1)根据乘法分配律进行简算;
(2)先算除法,再算乘法,最后算减法;
(3)根据连减的性质,算中括号里面的,最后算乘法;
(4)根据乘法分配律进行简算;
(5)根据乘法交换律和结合律进行简算;
(6)根据乘法分配律进行简算.
点评:完成本题要注意分析算式中数据,运用合适的简便方法计算.