Rotation symmetry in the 4th grade

After introducing the LearnToLearn set the kids in my 4th grade had to build an area out of 5-6 lego bricks of different colours. Then they turned it around and drew the pattern area into their exercise books. Afterwards we built mill or wind wings and did the same. You also could do it like this: the kids build a mill and let it work. They observe the wings and find out the rotation symmetry. Then they can build one wing and do the same like we did. You can see, this isn't just a game. Some pupils needed the help of the others or the teacher.