On the game virtual villagers i dont know what the 4th puzzle was. The pencil picture one. pls help?

Answer 1

The 4th puzzle is the large building. One of your villagers needs to be a master scienctist to open a school. When one is just place them on that large building and it should open up a school and give you Tech points for your new children when they are born. I am still playing and only have opened 5 puzzles.