There are 6!/2! = 360 ways.
The numbers are -10 and -70
10/2
-10/1, or +20/(-2)
4 and 2/10 + 3 and 3/10
2 + 3 + 5 = 10
numbers are less than or equal to 10: 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 and all the negative numbers
1+2+3+4+5+6+7+(8x9)=100
44
Not counting negative numbers (which would give you an infinite number of ways of adding numbers together to equal 10), there are 6 different ways (permutations) of adding numbers together to equal 10. 0 + 10 1 + 9 2 + 8 3 + 7 4 + 6 5 + 5
-82
2 x 5