题目内容
计算下面各题,能用简便方法算的要用简便方法算
×
+
÷
×[(
-
)÷
]
-
+
×
25×1.25×4×8.
| 7 |
| 13 |
| 5 |
| 6 |
| 5 |
| 6 |
| 13 |
| 6 |
| 4 |
| 15 |
| 3 |
| 4 |
| 2 |
| 5 |
| 15 |
| 4 |
| 7 |
| 8 |
| 4 |
| 5 |
| 3 |
| 8 |
| 1 |
| 3 |
25×1.25×4×8.
(1)
×
+
÷
,
=
×
+
×
,
=(
+
)×
,
=1×
,
=
;
(2)
×[(
-
)÷
],
=
×[(
-
)×
],
=
×[
×
],
=
×
,
=
;
(3)
-
+
×
=
-
+
,
=
+
-
,
=1-
,
=
;
(4)25×1.25×4×8,
=(25×4)×(1.25×8),
=100×10,
=1000.
| 7 |
| 13 |
| 5 |
| 6 |
| 5 |
| 6 |
| 13 |
| 6 |
=
| 7 |
| 13 |
| 5 |
| 6 |
| 5 |
| 6 |
| 6 |
| 13 |
=(
| 7 |
| 13 |
| 6 |
| 13 |
| 5 |
| 6 |
=1×
| 5 |
| 6 |
=
| 5 |
| 6 |
(2)
| 4 |
| 15 |
| 3 |
| 4 |
| 2 |
| 5 |
| 15 |
| 4 |
=
| 4 |
| 15 |
| 15 |
| 20 |
| 8 |
| 20 |
| 4 |
| 15 |
=
| 4 |
| 15 |
| 7 |
| 20 |
| 4 |
| 15 |
=
| 4 |
| 15 |
| 7 |
| 75 |
=
| 28 |
| 1125 |
(3)
| 7 |
| 8 |
| 4 |
| 5 |
| 3 |
| 8 |
| 1 |
| 3 |
=
| 7 |
| 8 |
| 4 |
| 5 |
| 1 |
| 8 |
=
| 7 |
| 8 |
| 1 |
| 8 |
| 4 |
| 5 |
=1-
| 4 |
| 5 |
=
| 1 |
| 5 |
(4)25×1.25×4×8,
=(25×4)×(1.25×8),
=100×10,
=1000.
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