2 ÷
4
2
2 -
3
1
20 ×
5
20 ×
5
1
5 +
2
3
4
2 ÷
2
4
9 +
1
20 ×
5
1 -
3
1
3
5
4
2
3
3
1 -
5
4
3 +
2
1