Opening and closing cereal boxes, cookie packages, books, etc. with letters, numbers, pictures printed on them.
understanding the Concept of מבטל כלי מהיכנו (Nullifying a Vessel from Its Usage);
Important Situations to Be Aware of That Arise in Reference to Kotzair;
An Interesting Situation That Sometimes Arises Regarding the Melacha of Tzod (Trapping);