- Begin by asking students if a balloon can be blown up inside bottle.
- Have a few students come up, push a deflated balloon into one of the bottles and stretch the open end of the balloon over the bottles mouth (you may need to help).
- Ask each of them to try blowing the balloon up (you may want to have some extra bottles handy as to prevent .
- Once every student has had a try, have a discussion on some reasons why the balloon would not blow up.
- (Air takes up space and that is why the balloon would not blow up.)