怎样算简便就怎样算.49×15÷45;4-511-611;18×58+42÷8;36×(23+16-34);(15-14×47)×821;45÷58-12÷58.-数学

8×58+42×
1
8

=(58+42)×
1
8

=100×
1
8

=12.5;

(4)36×(
2
3
+
1
6
-
3
4

=36×
2
3
+36×
1
6
-36×
3
4

=24+6-27,
=3;

(5)(15-14×
4
7
)×
8
21

=(15-8)×
8
21

=7×
8
21

=
8
3


(6)
4
5
÷
5
8
-
1
2
÷
5
8

=
4
5
×
8
5
-
1
2
×
8
5

=(
4
5
-
1
2
)×
8
5

=
3
10
×
8
5

=
12
25

据专家权威分析,试题“怎样算简便就怎样算.49×15÷45;4-511-611;18×58+42÷8;36×(23+1..”主要考查你对  运算定律和简便算法  等考点的理解。关于这些考点的“档案”如下:

运算定律和简便算法