题目内容
| 计算下面各题.(能简算的要简算) | ( | |
| (1+25%)÷(1-25%) | 5× |
解:
(1)
,
=
,
=3×
,
=
;
(2)(
)÷
,
=(
)×
,
=
×(
×
),
=
×1,
=
;
(3)
75%,
=
,
=
,
=1×0.75,
=0.75;
(4)(1+25%)÷(1-25%),
=1.25÷0.75,
=
;
(5)5×
,
=
+
,
=7;
(6)
÷65%×
×65%,
=(
×
)×(65%÷65%),
=
×1,
=
.
分析:(1)根据乘法分配律进行计算;
(2)根据乘法结合律进行计算;
(3)根据乘法分配律进行计算;
(4)先算加法和减法,再算除法;
(5)先算乘法,再算加法;
(6)根据乘法交换律和结合律进行计算.
点评:考查了运算定律与简便运算,四则混合运算.注意运算顺序和运算法则,灵活运用所学的运算律简便计算.
(1)
=
=3×
=
(2)(
=(
=
=
=
(3)
=
=
=1×0.75,
=0.75;
(4)(1+25%)÷(1-25%),
=1.25÷0.75,
=
(5)5×
=
=7;
(6)
=(
=
=
分析:(1)根据乘法分配律进行计算;
(2)根据乘法结合律进行计算;
(3)根据乘法分配律进行计算;
(4)先算加法和减法,再算除法;
(5)先算乘法,再算加法;
(6)根据乘法交换律和结合律进行计算.
点评:考查了运算定律与简便运算,四则混合运算.注意运算顺序和运算法则,灵活运用所学的运算律简便计算.
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