Miniminds (or a magnet workshop) Make science fun and playful by making a magnet powered car! Make a road and see if you can push/pull your car in the right direction without touching it.
How Strong is Spaghetti? STEM Challenge for Kids! Create tests to investigate the strength of spaghetti.
RT @lnsnare: only regret i have in my life was wasting time and energy on people who actually never even cared about me
LEGO Gravity Rollers: A Fun Contraption That Propels Itself! Fantastic STEM project for kids. Will this work for Scout requirement?