Count me in as a big mouth! Most stores have a simple requirement i.e. to convert as an example 3/4 to .75 so they can prepare the sale slip for the cash if they don't have a scanner to do it, The clerks are paid minimum wages would the store ask for sewing knowledge, it would become a specialized job which would mean higher salary to pay for the owner of the store. The unknown rule is that the store is not responsible for informations given by a clerk to a customer because this is outside of their job definition, Going back to the post , the clerk was there to cut exactly what the young girl ordered, The clerk that ask you questions is doing it on her own!