National Council of Teachers of Mathematics
The Math Forum: Lesson Plans: Fractions
Teachers, this is the place to come for fraction lesson plans if you teach elementary students. All the topics have a number of resources available from which to choose.
The Math League
The Math League: Decimals, Whole Numbers and Exponents
This tutorial has definitions and examples of decimals, whole numbers, and exponents. In addition, a variety of topics are covered, such as comparing, multiplying and subtracting.
Discovery Education
Discovery Education: Web Math: What Is a Fraction?
This WebMath site provides an interactive fraction solver which not only brings back an answer, but also includes a full visual description of what a fraction is and how the answer was accomplished.
National Council of Teachers of Mathematics
The Math Forum: Intro to Fractions for Primary Students
This site from the Math Forum is a series of lesson plans with great ideas and an excellent Web site that uses virtual manipulatives with students.