Budding chemists aren't the only ones who will get a kick out of this enjoyable experiment that teaches something about how the natural world works. When baking soda and vinegar come into contact, they form carbon dioxide. This gas fills the bottle and can't escape, so it rushes into the balloon, causing it to inflate.
Take everyone for a stroll down memory lane with photos of the guest of honor. Include shots from all eras, with lots of friends and family. Unify the images -- and give them classic vintage appeal -- by printing them in black-and-white.
Part of a pinata's unique charm is that no matter how ornate it is or how much time went into making it, its decorative qualities are entirely temporary. Stuffed with candy and treats, the pinata is meant to be smashed apart, spilling its contents into the hands of the children clustered around it at parties.
There's logic to the notion of an obstacle-course-themed birthday party considering how many real-life obstacles an 8-year-old has surmounted. Each little triumph of language and locomotion has been a confidence-building occasion.