How many rubber bands will it take to make a pumpkin explode?! Every student loves a hands on activity where vegetables explode with just the use of rubber bands.
You can access videos online of different (older students) doing this experiment in their classroom while investigating the pumpkins diameter, circumference, etc. But for elementary, we are just going to look at the basic principles of force and pressure on an object.
There are 6 varied worksheets in this file that you can use to assist you in this investigation. I usually get 3 pumpkins of varying sizes to use with my class and make a classroom graph to see the relationships between a pumpkins size and weight, and how many rubber bands it took for it to explode. Some worksheets include weight, size (drawings) and predictions/results for what happened. The last page is a bar graph for looking at the 3 pumpkins explosions.