Scholastic
Scholastic: Math Maven's Mysteries: The Secret of E. Quation the Great
Want to figure out a magician's secret for a cool balancing trick? Use your algebra knowledge to discover how this magic trick was done.
Other
Tufts University: Early Algebra, Early Arithmetic
This online resource is from the Tufts University offers lesson plans, worksheets, and ideas about using algebra with elementary grade levels.
The Math League
The Math League: Introduction to Algebra
This introduction offers help on a variety of topics in algebra, such as variables, expressions, equations, and simplifying.