Answer:
1+3=4, 2+4=6, 5+6=11
Explanation:
when made into a cube, (assuming 2 is on the top,) 1 is on the left side and 3 is on the right. 2 is on the top and 4 is on the bottom. 5 is on the north side (the front I guess, but north is the way I can explain it best) and 6 is on the south (the back).