题目内容
(1)84×(
-
)
(2)
+(
+
)×
(3)
÷
+
×8.
| 3 |
| 4 |
| 1 |
| 3 |
(2)
| 3 |
| 8 |
| 3 |
| 7 |
| 1 |
| 14 |
| 2 |
| 3 |
(3)
| 11 |
| 12 |
| 1 |
| 8 |
| 13 |
| 12 |
分析:(1)运用乘法分配律简算;
(2)先算括号内的,再算括号外的乘法,最后算加法;
(3)把除法改为乘法,运用乘法分配律简算.
(2)先算括号内的,再算括号外的乘法,最后算加法;
(3)把除法改为乘法,运用乘法分配律简算.
解答:解:(1)84×(
-
)
=84×
-84×
=63-28
=35;
(2)
+(
+
)×
=
+
×
=
+
=
;
(3)
÷
+
×8
=
×8+
×8
=(
+
)×8
=2×8
=16.
| 3 |
| 4 |
| 1 |
| 3 |
=84×
| 3 |
| 4 |
| 1 |
| 3 |
=63-28
=35;
(2)
| 3 |
| 8 |
| 3 |
| 7 |
| 1 |
| 14 |
| 2 |
| 3 |
=
| 3 |
| 8 |
| 1 |
| 2 |
| 2 |
| 3 |
=
| 3 |
| 8 |
| 1 |
| 3 |
=
| 17 |
| 24 |
(3)
| 11 |
| 12 |
| 1 |
| 8 |
| 13 |
| 12 |
=
| 11 |
| 12 |
| 13 |
| 12 |
=(
| 11 |
| 12 |
| 13 |
| 12 |
=2×8
=16.
点评:要想算得快、算得巧,就要仔细注意观察题目中数字构成的特点和规律,运用运算定律或运算技巧,进行简便计算.
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