How do these three things go together?
Teach your kids a little bit of science and learn about dry ice.
This page has a lot of fun facts and ideas of things you can add to this idea with: http://www.stevespanglerscience.com/experiment/dry-ice-fun-learning-about-dry-ice
Then plan a weekend fun activity with the family or if you are doing a BBQ or 4th of July celebration add this to your list of things to do and show them dry ice in action!
4 lbs of sugar
2 oz of Root Beer Concentrate
4 gallons of water
4 lbs of dry ice.
Mix everything but the dry ice in a clean 5 gallon bucket. Then add your dry ice and stir once in awhile to keep the dry ice off the bucket. When the dry ice dissolves in about 20 minutes or so you have root beer to enjoy!
The kids will love how it looks like a witches brew as it is melting and that's a great time to tell them all about dry ice.
It is really easy to do (wear gloves handling the dry ice) and inexpensive. 5 gallons of root beer costs approximately $10.00.
Where to find dry ice? Check with your local grocers as a lot of them carry it or google your city, state and dry ice. There are various resources for this information.