Balloons

Today we went to a birthday party for a 2-year old. Daughter had a lovely time and there were 7 children in total - on the way out she received a helium balloon. Once we got home she tried tying a doll to it only to find that this dragged the balloon down - "The doll is too heavy for the balloon" so she untied it. We then used hair tyes and added them one-by-one and watched for the balloon to dip down. It was a nice little observation and it was interesting to notice her experimenting with the science without any explanation.