(I'm here again asking questions...) This puzzle is the fifth one from Brian Chen's Spalsh 2016 hunt. I thought I can solve it but stuck at the last step (maybe). Here is the whole puzzle: How I tried: SPOILER SPOILER

1*1=1 1+1=2 round(square root(11))=3 roundup(square root(11)=4 round(1φ)+round(1π)=5 round(1φ)+roundup(1π)=6 round(1π)+roundup(1π)=7 roundup(1π)+roundup(1π)=8 1/.1~=9 1/.1=10

This is a Light Up (aka Akari) puzzle, except it is on what is called a real projective plane. A real projective plane is, simply put, just a Möbuis strip with a single edge except for the fact that the opposite open edges are also glued together. This is different from a Klein Bottle because a K...