4th graders fraction activity "fraction operations"

During a recent learning exercise in Ms. Alison Reef's 4th-grade classroom, students were asked to pretend each was a Medical Doctor!  Each Doctor (student) had a "patient folder" with patient notes and a picture of a body where answers were to be recorded.   Various teacher-created "bodies" were supplied to meet the needs of individual students.  As each patient was missing some body part, students were asked to decide what was missing, explain their hypothesis, and then do what was necessary to "save the patient's life"!  The purpose of the exercise was to illustrate the addition of a number to a group and see the whole in the study of fractions.  The exercise used some anatomical science to illustrate the need for math in daily life functions!