题目内容
| 下面各题,怎样简便就怎样算. 39÷7+31×
| 0.625×36+
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|
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| (
|
(1)39÷7+31×
,
=(39+31)×
,
=70×
,
=10;
(2)0.625×36+
×36-36,
=(0.625+0.375-1)×36,
=0×36,
=0;
(3)
÷[(
-
)+(
-
)],
=
÷[
+
],
=
÷
,
=
;
(4)
×2008-2007,
=
×2009-
×1-2007,
=2008-
-2007,
=1-
,
=
;
(5)
+
+
+
+
+
+
+
,
=1-
+
-
+
-
+
-
+
-
+
-
+
-
+
+
-
,
=1-
,
=
;
(6)(
+
)×27×9,
=
×72×9+
×27×9,
=144+45,
=189.
| 1 |
| 7 |
=(39+31)×
| 1 |
| 7 |
=70×
| 1 |
| 7 |
=10;
(2)0.625×36+
| 3 |
| 8 |
=(0.625+0.375-1)×36,
=0×36,
=0;
(3)
| 4 |
| 9 |
| 5 |
| 6 |
| 1 |
| 2 |
| 5 |
| 9 |
| 5 |
| 18 |
=
| 4 |
| 9 |
| 1 |
| 3 |
| 5 |
| 18 |
=
| 4 |
| 9 |
| 11 |
| 18 |
=
| 8 |
| 11 |
(4)
| 2008 |
| 2009 |
=
| 2008 |
| 2009 |
| 2008 |
| 2009 |
=2008-
| 2008 |
| 2009 |
=1-
| 2008 |
| 2009 |
=
| 1 |
| 2009 |
(5)
| 1 |
| 2 |
| 1 |
| 6 |
| 1 |
| 12 |
| 1 |
| 20 |
| 1 |
| 30 |
| 1 |
| 42 |
| 1 |
| 56 |
| 1 |
| 72 |
=1-
| 1 |
| 2 |
| 1 |
| 2 |
| 1 |
| 3 |
| 1 |
| 3 |
| 1 |
| 4 |
| 1 |
| 4 |
| 1 |
| 5 |
| 1 |
| 5 |
| 1 |
| 6 |
| 1 |
| 6 |
| 1 |
| 7 |
| 1 |
| 7 |
| 1 |
| 8 |
| 1 |
| 8 |
| 1 |
| 8 |
| 1 |
| 9 |
=1-
| 1 |
| 9 |
=
| 8 |
| 9 |
(6)(
| 2 |
| 9 |
| 5 |
| 27 |
=
| 2 |
| 9 |
| 5 |
| 27 |
=144+45,
=189.
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