题目内容
用简便方法计算
|
|
67×
|
|
(1)
×
+
÷
=
×
+
×
,
=
×(
+
),
=
×1,
=
;
(2)
×99+
=(99+1)×
,
=100×
,
=70;
(3)67×
=(66+1)×
,
=66×
+
,
=5+
,
=5
;
(4)
×13+
×5
=
×13+
×13,
=(
+
)×13,
=1×13,
=13.
3 |
8 |
2 |
7 |
3 |
8 |
7 |
5 |
=
3 |
8 |
2 |
7 |
3 |
8 |
5 |
7 |
=
3 |
8 |
2 |
7 |
5 |
7 |
=
3 |
8 |
=
3 |
8 |
(2)
7 |
10 |
7 |
10 |
=(99+1)×
7 |
10 |
=100×
7 |
10 |
=70;
(3)67×
5 |
66 |
=(66+1)×
5 |
66 |
=66×
5 |
66 |
5 |
66 |
=5+
5 |
66 |
=5
5 |
66 |
(4)
3 |
8 |
13 |
8 |
=
3 |
8 |
5 |
8 |
=(
3 |
8 |
5 |
8 |
=1×13,
=13.
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