Question 175659
It's not that easy drawing a tree diagram.
It's much easier with paper and pencil.
I've shown the complete tree for the first roll of a 1. 
Then the second roll could be 1-6. 
The sum is then also shown. 
The complete tree diagram would also show similar trees for the second roll for 2-6. 
I'll leave that for you to complete in addition to the sums.
{{{drawing( 300, 300, -5, 8, -5, 5,
line(-4.5,0,-2,3.571),
line(-4.5,0,-2,2.142),
line(-4.5,0,-2,0.713),
line(-4.5,0,-2,-0.713),
line(-4.5,0,-2,-2.142),
line(-4.5,0,-2,-3.571),
locate(-1.8,4.1,1),
locate(-1.8,2.5,2),
locate(-1.8,1.1,3),
locate(-1.8,-.5,4),
locate(-1.8,-1.9,5),
locate(-1.8,-3.3,6),
line(-1.2,4.1,3,4.8),
line(-1.2,4.1,3,4.4),
line(-1.2,4.1,3,4.0),
line(-1.2,4.1,3,3.6),
line(-1.2,4.1,3,3.2),
line(-1.2,4.1,3,2.8) ,


locate(3.2,5.0,1  : Sum=1+1=2),
locate(3.2,4.6,2  : Sum=1+2=3),
locate(3.2,4.2,3  : Sum=1+3=4),
locate(3.2,3.8,4  : Sum=1+4=5),
locate(3.2,3.4,5  : Sum=1+5=6),
locate(3.2,3.0,6  : Sum=1+6=7)

)}}}