题目内容
脱式计算.(能简算的要简算)
(1)
÷
+
÷
(2)36×
+24÷
(3)(
-
)÷
.
(1)
| 1 |
| 4 |
| 1 |
| 3 |
| 2 |
| 3 |
| 1 |
| 2 |
(2)36×
| 5 |
| 8 |
| 8 |
| 5 |
(3)(
| 3 |
| 4 |
| 2 |
| 3 |
| 5 |
| 12 |
分析:(1)把除法改为乘法,先算乘法,再算加法;
(2)把除法改为乘法,运用乘法分配律的逆运算简算;
(3)先算括号内的,再算括号外的,注意约分.
(2)把除法改为乘法,运用乘法分配律的逆运算简算;
(3)先算括号内的,再算括号外的,注意约分.
解答:解:(1)
÷
+
÷
,
=
×3+
×2,
=
+
,
=2
;
(2)36×
+24÷
,
=36×
+24×
,
=(36+24)×
,
=60×
,
=37
;
(3)(
-
)÷
,
=
×
,
=
.
| 1 |
| 4 |
| 1 |
| 3 |
| 2 |
| 3 |
| 1 |
| 2 |
=
| 1 |
| 4 |
| 2 |
| 3 |
=
| 3 |
| 4 |
| 4 |
| 3 |
=2
| 1 |
| 12 |
(2)36×
| 5 |
| 8 |
| 8 |
| 5 |
=36×
| 5 |
| 8 |
| 5 |
| 8 |
=(36+24)×
| 5 |
| 8 |
=60×
| 5 |
| 8 |
=37
| 1 |
| 2 |
(3)(
| 3 |
| 4 |
| 2 |
| 3 |
| 5 |
| 12 |
=
| 1 |
| 12 |
| 12 |
| 5 |
=
| 1 |
| 5 |
点评:此题是考查四则混合运算的顺序以及简便计算,要仔细观察算式的特点,灵活运用一些定律进行简算.
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