题目内容
| 递等式计算(能简算的要简算) | (2- | |
| 75%×53+47×0.75 | 24×( |
解:(1)
×
+6,
=
+6,
=6
;
(2)
+3÷
,
=
+3×2,
=
+6,
=6
;
(3)(2-
×16)+
,
=(2-2)+
,
=
;
(4)75%×53+47×0.75,
=0.75×53+47×0.75,
=0.75×(53+47),
=0.75×100,
=75;
(5)24×(
+
-
),
=24×
+24×
-24×
,
=8+6-10,
=4;
(6)
÷
÷
,
=
×
×
,
=
.
分析:(1)先算乘法,再算加法;
(2)先算出发,再算加法;
(3)先算括号内的乘法,再算括号内的减法,最后算加法;
(4)把75%化为小数,运用乘法分配律简算;
(5)运用乘法分配律简算;
(6)把除法改为乘法,约分计算.
点评:此题考查了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进行简便计算.
=
=6
(2)
=
=
=6
(3)(2-
=(2-2)+
=
(4)75%×53+47×0.75,
=0.75×53+47×0.75,
=0.75×(53+47),
=0.75×100,
=75;
(5)24×(
=24×
=8+6-10,
=4;
(6)
=
=
分析:(1)先算乘法,再算加法;
(2)先算出发,再算加法;
(3)先算括号内的乘法,再算括号内的减法,最后算加法;
(4)把75%化为小数,运用乘法分配律简算;
(5)运用乘法分配律简算;
(6)把除法改为乘法,约分计算.
点评:此题考查了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进行简便计算.
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