题目内容
| 下面各题,怎样简便就怎样算 | |
| 8.5-(5.6+4.8)÷1.3 |
解:(1)
÷
÷
,
=
×
×
,
=
;
(2)
×
+
×
,
=
×(
+
),
=
×1,
=
;
(3)
×32×4×
=24;
(4)
÷(3-
-
),
=
÷[3-(
+
)],
=
÷[3-1],
=
÷2,
=
×
,
=
;
(5)8.5-(5.6+4.8)÷1.3,
=8.5-10.4÷1.3,
=8.5-8,
=0.5;
(6)
÷(
-
×
),
=
÷(
-
),
=
÷
,
=
×
,
=
.
分析:(1)把除法改为乘法,约分即可;
(2)运用乘法分配律简算;
(3)约分计算;
(4)括号内运用减法的性质简算,最后算除法;
(5)先算括号内的,再算括号外的除法,最后算减法;
(6)先算括号内的乘法,再算括号内的减法,最后算括号外的除法.
点评:此题考查了小数、分数的四则混合运算,注意运算顺序和运算法则,灵活运用所学的运算定律或性质进行简便计算.
=
=
(2)
=
=
=
(3)
(4)
=
=
=
=
=
(5)8.5-(5.6+4.8)÷1.3,
=8.5-10.4÷1.3,
=8.5-8,
=0.5;
(6)
=
=
=
=
分析:(1)把除法改为乘法,约分即可;
(2)运用乘法分配律简算;
(3)约分计算;
(4)括号内运用减法的性质简算,最后算除法;
(5)先算括号内的,再算括号外的除法,最后算减法;
(6)先算括号内的乘法,再算括号内的减法,最后算括号外的除法.
点评:此题考查了小数、分数的四则混合运算,注意运算顺序和运算法则,灵活运用所学的运算定律或性质进行简便计算.
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