As we could "drag" these together, we could then do it the easy way.
56
+56
+56
-------
168
------------------------
Or we could also do the following:
56
3:
63= 18.
Carry the one.
53 = 15+1 (which was carried). = 16
(16+8) = 168
56
+56
+56
-------
168
------------------------
Or we could also do the following:
56
6
Carry the one.
5
(16+8) = 168