1 -
2
1
7 +
5
12 ×
3
4
1 -
4
3
2
6 +
1
5
15 ×
3
5
8 ×
4
2
3 +
1
5 ÷
1
8 ×
4
8 +
3
5
2
5
2
4 ÷
1
4
3
3