Attendance as they walk in! A quick get to know you/math (counting and graphing) activity. Later in the year students can generate the questions and write them. Place on light colored paper, laminate, and questions can be added with white board marker.
Trees study- From: I'm a teacher, get me OUTSIDE here! Sorting sticks from longest to shortest. Good outdoor group activity for preschoolers that can be left for individual students to return to time and again.