36306

You can only add 8 times to equal "7" you can add:
1. 5+2=7
2. 2+5=7
3. 1+6=7
4. 6+1=7
5. 3+4=7
6. 4+3=7
7. 7+0=7
8. 0+7=7

It wasn't very hard and was really fun, It was very good and it ws enjoyable