Some scavenger hunts can always be a fun way to test and see if the children has a conception of the subject matter.
I have found two good ones:
STEM-Building-Challenge-and-Scavenger-Hunt-Frugal-Coupon-Living (PDF 281 kB) This one includes some building challenges also. It was found from Frugal Coupon Living where you can find a whole lot of other resources.
The other one is a JPG. (Click on it for more proper size)
