题目内容
计算9×
时,( )的计算方法简便.
7 |
8 |
A.(10-1)×
| B.(8+1)×
| C.9×(1-
|
9×
,
=(8+1)×
,
=8×
+1×
,
=7+
,
=7
.
故选:B.
7 |
8 |
=(8+1)×
7 |
8 |
=8×
7 |
8 |
7 |
8 |
=7+
7 |
8 |
=7
7 |
8 |
故选:B.
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