题目内容
用递等式计算. (能简算的要简算)
|
|
3.7×99+3.7 | ||||||||||||||
|
360÷15+2.5×16 |
|
分析:(1)(2)(5)(6)依据四则运算顺序,先算第二级运算,再算第一级运算,如果只含有同一级运算,按照从左到右顺序计算,有括号先算括号里面的顺序解答,
(3)运用乘法分配律解答,
(4)运用加法交换律和结合律解答.
(3)运用乘法分配律解答,
(4)运用加法交换律和结合律解答.
解答:解:(1)
×(
÷
),
=
×
,
=
;
(2)
+
÷
,
=
+
,
=2;
(3)3.7×99+3.7,
=3.7×(99+1),
=3.7×100,
=370;
(4)
+
+
+
,
=(
+
)+(
+
),
=1+1,
=2;
(5)360÷15+2.5×16,
=24+40,
=64;
(6)
÷〔1-(
-
)〕,
=
÷〔1-
〕,
=
÷
,
=
.
3 |
5 |
5 |
12 |
3 |
4 |
=
3 |
5 |
5 |
9 |
=
1 |
3 |
(2)
5 |
6 |
7 |
12 |
1 |
2 |
=
5 |
6 |
7 |
6 |
=2;
(3)3.7×99+3.7,
=3.7×(99+1),
=3.7×100,
=370;
(4)
3 |
7 |
5 |
11 |
4 |
7 |
6 |
11 |
=(
3 |
7 |
4 |
7 |
5 |
11 |
6 |
11 |
=1+1,
=2;
(5)360÷15+2.5×16,
=24+40,
=64;
(6)
2 |
3 |
1 |
3 |
1 |
4 |
=
2 |
3 |
1 |
12 |
=
2 |
3 |
11 |
12 |
=
8 |
11 |
点评:本题主要考查学生依据四则运算顺序,以及简便方法正确解决问题的能力.
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