问题
解答题
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)
更正:______ (2)72×
=(72×
=1÷1 =1 更正:______ (3)(
=
=3-2 =1 更正:______ (4)
=
=1+
=1
更正______. |
答案
(1)
,
+7 8
×1 8 4 5
=
+7 8
,1 10
=
;39 40
(2)72×
÷72×5 8
,5 8
=(72÷72)×(
×5 8
),5 8
=1×
,25 64
=
;25 64
(3)(
-3 5
)×5×7,2 7
=
×5×7-3 5
×5×7,2 7
=21-10,
=11;
(4)
÷(8 15
+8 15
),4 5
=
÷8 15
,4 3
=
.2 5