0 5
1 6
2 7
3 8
4 9
Because it's a cycle, you have to work in pairs:
3 8
×
4 9
We can get: 3+9 = 4+8 >; 0+7= 1+6=2+5
②:
Think in the same way:
Arrange the number 10 in two columns:
0 5
1 6
2 7
3 8
4 9
Right minus left: 9-4=8-3=7-2=6- 1=5-0=→↓
↑←←←←←←←←←←
You mean this?