I find that it is often difficult to teach young children about veterans and the military. But their brave service is too special to disregard. Typically it seems that those figures are most easily described something like fire fighters or police- people who are brave and help others.
After discussing the flag and looking at photos of service men and women, we played this counting game. Each player has a sheet of stars and takes a turn rolling a 6 sided die. The children counted the die and colored in the corresponding number of stars.