脱式计算,写出主要计算过程,能用简便算法的要用简便算法. ①12× 3 8 ÷ 3 4

2024-11-23 01:59:41
推荐回答(1个)
回答1:

①12×
3
8
÷
3
4

=12×
3
8
×
4
3

=6;
4
9
+
5
9
×9
=
4
9
+5
=5
4
9

③14÷(
1
3
+
5
6
)×
3
4

=14÷
7
6
×
3
4

=14×
6
7
×
3
4

=9;
④3.6-2.8+16.4-7.2
=(3.6+16.4)-(2.8+7.2)
=20-10
=10;
⑤77×
4
5
+23×0.8
=(77+23)×0.8
=100×0.8
=80.