Iluminations, from the National Council of Teachers of Mathematics provides math teachers with lesson plans and interactives to use in the classroom. These activities get students out of the textbook and help reach those with multiple learning styles.  Teachers can also search by specific standards and each lessons provides the objectives, materials needed, assessment, reflections, and related resources.   I encourage any K-12 math educator to check out the Illuminations site.  Not only does this site have tons of resources for teachers and students but they are all FREE!