>>1
Because it's not that fucking difficult to just remember. Repeat after me: 1,2,3,4,53,63,742,23,23,2,1,2,31,42-4,53-3,64-2,731-1.
If you've paid any attention to the irregularities in the filling order of orbitals (eg Cu = [Ar] 4s2 3d17 4p2, not d18 p1) - hell, they may even BE in your poster - the exceptions to this are easy enuff to work out.