Hi! I'm a first year teacher who was hired for fifth grade in June but found out last week I will be teaching second grade now. School starts Monday, so I don't have much time to prepare. I really want to have a small science center in my room with different objects for the students to look at/manipulate/observe. My school only gave me $100 and that's long gone, so I want this stuff to be cheap. However, I'm willing to put in the time and effort to make it decent. What kinds of items do you suggest?