第79页

信息发布者:
9
17
=280÷5÷7
=56÷7
=8
=600÷(12×5)
=600÷60
=10
3
4
B
A
9
3
27
9
8
72
81
18
2
3
6
8
5
8
8
0
6
3
0
0
8
8
4
9
6