This is a great activity to begin the day, but you will need to leave a little more time than you do for most bell works. Set one pumpkin on each table. Have each group estimate the number of seeds they think will be in the pumpkin. Then as a group, your kids will count the seeds and compare this amount to their estimations. You may want to have the tops cut before the activity and just tell your class not to look inside until they have given their estimations. Then have the whole class compare the amount of seeds found in the pumpkins and come up with an overall average.