This is a great lesson to do around Halloween or anytime in the fall. It ties in math skills by introducing weight and circumference in a fun way. This can all be done in one session (about 2 - 3 hours) or it can be spread out over 3 or 4 days whichever suits your class needs. The activity involves using real pumpkins to weigh and measure and construction-paper pumpkins to record the students' estimates and actual measures. This activity can be done whole-group, but it works best if it is done in an adult-supervised center or on days when you have several parent volunteers.