Math Help
Help with Rounding

"Sig Fig" song

Crash Course Chem Unit conversion and Sig Figs

Unit Conversion short video

Dimensional Analysis parody

Converting Units (uses english and metric units)

This seems to be a good site to practice unit conversions.  I have not been through every example, but try it and let me know what you think.  It mentions it works better in browsers other than chrome, so if you are having trouble switch.

You could also go to his main website and find other resources for his class called CP Chem.