Understanding the constructive and destructive part of it (mochaik).
Putting the Little Plastic or Rubber Cups on the Bottom of Chairs or Tables and Blowing Bubbles on Shabbos;
Giving Out Tickets to Children for Learning Well. If One Finds a Mistake in a Sefer on Shabbos. Index Cards for an עליה;
putting back a window screen; putting back a window screen .