Wyzant
Wyzant: What Is Simplifying?
This site from WyzAnt explores what simplifying is, as well as how to simplify a variety of algebraic equations. Content focuses on simplifying multiple signs, combining like terms, simplifying multiplication, distributing a number or...
University of Waterloo (Canada)
University of Waterloo: Cemc: Math Circles: Exponents [Pdf]
This instructional activity provides exercises in writing expressions in exponential form, multiplying and dividing powers, and working with zero and negative exponents. A series of challenging word problems are included.