Give each student, pair of students, or groups of students the same amount of index cards and ask them to build the tallest tower. Students can then measure height and graph the results, they could time to see how long it stands up to the teacher or the same person blowing at a specific point. It would be interesting to see if it makes a difference of where it is hit with the wind and then could discuss why and what architects have to think about when designing buildings...etc So much you can do with just cards.
If you are home schooling or even at school, use what you have around the house to do building/design challenges. You can include tools such as tongs and mix materials...etc This gets students thinking critically and problem solving. It is also really good for students to see it fall and learn that its ok to make mistakes, ask them what they learned and to try again.
FORTS!! What better fun is there as a kid! Get them creating, having fun, thinking, and using what they build. Win-win all the way around!