That was what I saw also. I wanted you see what made me think of the die number. Eye is training is gaining knowledge. Given then answer, you don't know why we came to that conclusion. Thus I give clues to search for, then that trains your eye. Here is another thing I figured on on the 1972
DDO's:

Look to see why I created this image? Then answer back if you figure it out. (Applies to any and all) We'll make it a real class project?