You can make 12 different numbers.
89,999 different numbers i guess
98
With 4 different numbers, 24.
8
6, as long as they are all different
you can make at least 25 sums
Assuming that the six numbers are different, the answer is 15.
1000
about... 25 just take 5 numbers times 5 numbers
15
12 different numbers.
It would be 5 ways