Understanding the Difference Between טירחא יתירה (Tircha Yeseira, Major Exertion) and טירחא סתם (Tircha Stam, Minor Exertion) on Shabbos;
Using utensils, items that open and close by folding. (E.g., folding tables, strollers, playpens, folding chairs, etc.)
(Squeezing materials.) understanding the concept of wiping up spills with a towel or rag;