CK-12 Foundation
Ck 12: Arithmetic: Comparison of Ratios in Decimal Form
[Free Registration/Login may be required to access all resource tools.] Write and compare ratios in decimal form
Khan Academy
Khan Academy: Reducing Rational Expressions to Lowest Terms
Learn what it means to reduce a rational expression to lowest terms, and how it's done!
University of Waterloo (Canada)
Centre for Education in Mathematics and Computing: Ratio and Rate [Pdf]
Learners explore the concepts of rate and ratio in a variety of problem-solving situations. Worksheets contain definitions and visual representations of concepts. Link to related ratio game. Other skills include measurement, data...
Khan Academy
Khan Academy: Intro to Rational Expressions
This lesson will introduce you to rational expressions. You will learn how to determine when a rational expression is undefined and how to find its domain.