题目内容
怎样简便就怎样算.
÷6×
×
+
÷
-
-
1÷[
×(
+
)].
| 3 |
| 4 |
| 8 |
| 9 |
| 3 |
| 8 |
| 5 |
| 11 |
| 5 |
| 8 |
| 11 |
| 5 |
| 11 |
| 6 |
| 3 |
| 7 |
| 4 |
| 7 |
| 3 |
| 5 |
| 1 |
| 2 |
| 1 |
| 3 |
分析:(1)运用乘法交换律简算;
(2)把除法变成乘法,再运用乘法分配律简算;
(3)根据连续减去两个数等于减去这两个数的和简算;
(4)先算小括号里面的加法,再算中括号里面的乘法,最后算括号外的除法.
(2)把除法变成乘法,再运用乘法分配律简算;
(3)根据连续减去两个数等于减去这两个数的和简算;
(4)先算小括号里面的加法,再算中括号里面的乘法,最后算括号外的除法.
解答:解:(1)
÷6×
,
=
×
÷6,
=
÷6,
=
;
(2)
×
+
÷
,
=
×
+
×
,
=(
+
)×
,
=1×
,
=
;
(3)
-
-
,
=
-(
+
),
=
-1,
=
;
(4)1÷[
×(
+
)],
=1÷[
×
],
=1÷
,
=2.
| 3 |
| 4 |
| 8 |
| 9 |
=
| 3 |
| 4 |
| 8 |
| 9 |
=
| 2 |
| 3 |
=
| 1 |
| 9 |
(2)
| 3 |
| 8 |
| 5 |
| 11 |
| 5 |
| 8 |
| 11 |
| 5 |
=
| 3 |
| 8 |
| 5 |
| 11 |
| 5 |
| 8 |
| 5 |
| 11 |
=(
| 3 |
| 8 |
| 5 |
| 8 |
| 5 |
| 11 |
=1×
| 5 |
| 11 |
=
| 5 |
| 11 |
(3)
| 11 |
| 6 |
| 3 |
| 7 |
| 4 |
| 7 |
=
| 11 |
| 6 |
| 3 |
| 7 |
| 4 |
| 7 |
=
| 11 |
| 6 |
=
| 5 |
| 6 |
(4)1÷[
| 3 |
| 5 |
| 1 |
| 2 |
| 1 |
| 3 |
=1÷[
| 3 |
| 5 |
| 5 |
| 6 |
=1÷
| 1 |
| 2 |
=2.
点评:此题是考查四则混合运算,要仔细观察算式的特点,灵活运用一些定律进行简便计算.
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