题目内容
脱式计算(能简算的要简算)
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分析:(1)先算小括号里面的加法,再算括号外的除法,最后算括号外的加法;
(2)运用乘法分配律简算;
(3)按照从左到右的顺序计算;
(4)先算除法,再算乘法,最后算加法;
(5)先算小括号里面的加法,再算中括号里面的乘法,最后算括号外的加法;
(6)先把除法变成乘法,再运用乘法分配律简算.
(2)运用乘法分配律简算;
(3)按照从左到右的顺序计算;
(4)先算除法,再算乘法,最后算加法;
(5)先算小括号里面的加法,再算中括号里面的乘法,最后算括号外的加法;
(6)先把除法变成乘法,再运用乘法分配律简算.
解答:解:(1)
÷(0.8+
)+0.75,
=
÷1+0.75,
=
+0.75,
=1;
(2)(
+
-
)×12,
=
×12+
×12-
×12,
=3+8-2,
=9;
(3)
÷4×
,
=
×
,
=
;
(4)
+
÷
×
,
=
+
×
,
=
+2,
=2
;
(5)
+[(
+
)×
],
=
+[
×
],
=
+
,
=
;
(6)
×
+
÷
,
=
×
+
×
,
=
×(
+
),
=
×1,
=
.
| 1 |
| 4 |
| 1 |
| 5 |
=
| 1 |
| 4 |
=
| 1 |
| 4 |
=1;
(2)(
| 1 |
| 4 |
| 2 |
| 3 |
| 1 |
| 6 |
=
| 1 |
| 4 |
| 2 |
| 3 |
| 1 |
| 6 |
=3+8-2,
=9;
(3)
| 8 |
| 13 |
| 5 |
| 6 |
=
| 2 |
| 13 |
| 5 |
| 6 |
=
| 5 |
| 39 |
(4)
| 1 |
| 7 |
| 4 |
| 5 |
| 7 |
| 4 |
| 35 |
| 8 |
=
| 1 |
| 7 |
| 16 |
| 35 |
| 35 |
| 8 |
=
| 1 |
| 7 |
=2
| 1 |
| 7 |
(5)
| 1 |
| 5 |
| 2 |
| 3 |
| 1 |
| 5 |
| 1 |
| 15 |
=
| 1 |
| 5 |
| 13 |
| 15 |
| 1 |
| 15 |
=
| 1 |
| 5 |
| 13 |
| 225 |
=
| 58 |
| 225 |
(6)
| 7 |
| 18 |
| 1 |
| 4 |
| 3 |
| 4 |
| 18 |
| 7 |
=
| 7 |
| 18 |
| 1 |
| 4 |
| 3 |
| 4 |
| 7 |
| 18 |
=
| 7 |
| 18 |
| 1 |
| 4 |
| 3 |
| 4 |
=
| 7 |
| 18 |
=
| 7 |
| 18 |
点评:本题考查了四则混合运算,注意运算顺序和运算法则,灵活运用所学的运算定律进行简便计算.
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