For some additional practice or tutorials, please feel free to utilize the following resources:
IXL - https://www.ixl.com/science/grade-4
Energy Kids - http://www.eia.gov/kids/
Mr. Nussbaum Science - http://mrnussbaum.com/science/
Discovery Kids: Science - http://discoverykids.com/videos/science-friction-all-about-the-physics-of-curling-dnews/
BrainPop Science - https://www.brainpop.com/science/