July 14, 1997
We tried this at home with my 4th and 6th graders and had a difficult time NOT blowing the ball into the bottle. I had to work at it to get it to blow back in my face. We tried with different bottles and different paper wad sizes. I WAS able to put the straw into the bottle and suck in the ball. Having them blow into a pop bottle with their mouths on the opening did produce the answer that you can't because the bottle is full of air.

March 5, 1998
Why do you rate your projects according to grade level? I'm a student teacher, and I feel this demonstration and others would not only be appropriate for grade school kids, but students of any age. After all, I'm a college student and I found it facinating. I'm not advocating that the students submit lab reports on this stuff, I just think these would make great demos to capture the interest of ALL students.

Editor's Note: Most PUMAS examples would be fun and interesting for almost anyone with some curiosity and energy. We label examples with grade levels to give teachers, particularly at the younger grades, a way to filter out examples that might be too advanced for their students.