Google is a great resource however i don't recall EVER learning ohms law in 4th grade also in high school you need to learn biology and chemistry before physics (which ohms law falls under) I may be wrong about the physics thing because i was so upset with the high school teaching at such a ridiculous reading level even advanced classes!!! i just dropped out. I'm in homeschooling now learning at my own level and next year I'm headed over to Daytona Beach for II(Installer Institute) to learn ohms law from people who use it and calculate it everyday! Seriously though I'm 18 and I've learned more from google about algebra and English than any teacher i've had since pre-k. Parents homeschool your kids. Seriously