小马虎做作业,有一次粗心的他把下面的计算全做错了,请细心的你仔细观察他做错的原因,并帮他改正.(1)78+18×45=(78+18)×45=1×45=45更正:______(2)72×58÷72×58

题目简介

小马虎做作业,有一次粗心的他把下面的计算全做错了,请细心的你仔细观察他做错的原因,并帮他改正.(1)78+18×45=(78+18)×45=1×45=45更正:______(2)72×58÷72×58

题目详情

小马虎做作业,有一次粗心的他把下面的计算全做错了,请细心的你仔细观察他做错的原因,并帮他改正.
(1)
7
8
+
1
8
×
4
5
=(
7
8
+
1
8
4
5
=1×
4
5
=
4
5

更正:______
(2)72×
5
8
÷72×
5
8

=(72×
5
8
)÷(72×
5
8


=1÷1
=1
更正:______
(3)(
3
5
-
2
7
)×5×7
=
3
5
×5-
2
7×7

=3-2
=1
更正:______
(4)
8
15
÷(
8
15
+
4
5
)

=
8
15
÷
8
15
+
8
15
÷
4
5

=1+
2
3

=1
2
3

更正______.
题型:解答题难度:中档来源:不详

答案


(1)
class="stub"7
8
+class="stub"1
8
×class="stub"4
5

=class="stub"7
8
+class="stub"1
10

=class="stub"39
40


(2)72×class="stub"5
8
÷72×class="stub"5
8

=(72÷72)×(class="stub"5
8
×class="stub"5
8
),
=1×class="stub"25
64

=class="stub"25
64


(3)(class="stub"3
5
-class="stub"2
7
)×5×7,
=class="stub"3
5
×5×7-class="stub"2
7
×5×7,
=21-10,
=11;

(4)class="stub"8
15
÷(class="stub"8
15
+class="stub"4
5
)

=class="stub"8
15
÷class="stub"4
3

=class="stub"2
5

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