题目内容
脱式计算,能简便计算的要简便计算. 3×(150-1530÷15) |
[1-(
|
(1-0.95)÷0.01 | ||||||||
|
3.72×99+3.72 |
|
分析:(1)可按运算顺序计算;
(2)可按分数四则混合运算的运算顺序进行计算,先算小括号里面的;
(3)先算括号里面的减法,再算除法;
(4)可用加法结合律,先算(
+
)是多少;
(5)可运用乘法分配律进行简便计算;
(6)可把140看成(139+1)后,运用乘法分配律进行简便计算.
(2)可按分数四则混合运算的运算顺序进行计算,先算小括号里面的;
(3)先算括号里面的减法,再算除法;
(4)可用加法结合律,先算(
11 |
15 |
4 |
15 |
(5)可运用乘法分配律进行简便计算;
(6)可把140看成(139+1)后,运用乘法分配律进行简便计算.
解答:解:(1)3×(150-1530÷15)
=3×(150-102)
=3×48
=144;
(2)[1-(
-
)]×
=[1-
]×
=
;
(3)(1-0.95)÷0.01
=0.05÷0.01
=5;
(4)
+(
+
)
=(
+
)+
=1+
=1
;
(5)3.72×99+3.72
=3.72×(99+1)
=3.72×100
=372;
(6)
×140
=
×(139+1)
=
×139+
=111+
=111
;
故答案为144;
;5;1
;372;111
.
=3×(150-102)
=3×48
=144;
(2)[1-(
1 |
2 |
1 |
4 |
2 |
3 |
=[1-
1 |
4 |
2 |
3 |
=
1 |
2 |
(3)(1-0.95)÷0.01
=0.05÷0.01
=5;
(4)
11 |
15 |
4 |
15 |
5 |
9 |
=(
11 |
15 |
4 |
15 |
5 |
9 |
=1+
5 |
9 |
=1
5 |
9 |
(5)3.72×99+3.72
=3.72×(99+1)
=3.72×100
=372;
(6)
111 |
139 |
=
111 |
139 |
=
111 |
139 |
111 |
139 |
=111+
111 |
139 |
=111
111 |
139 |
故答案为144;
1 |
2 |
5 |
9 |
111 |
139 |
点评:此题是考查四则混合运算,要仔细观察算式的特点,灵活运用一些定律进行简便计算.
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