GeoGebra - A multi-platform mathematics software that gives everyone the chance to experience the extraordinary insights that mathematics makes possible. GeoGebra is a free software.

Desmos - Desmos is an online-only graphing tool. The site’s authors offer teachers free registration to access pre-made collaborative content for their classrooms. Learners can easily turn any given equation into a graph.

National Library of Virtual Manipulatives - NLVM is a free Java-run software websites for a variety of concepts from K-12.

Texas Instruments Math 'nSpired' Lesson Plan Resources - TI's Math 'nSpired Lesson Plan Resource is a place where you can access lesson plans that utilize the TI-nSpire calculator as a means of creating visual and collaborative lessons.

Geometer's Sketchpad - This software is well worth purchasing. It is a great software for not only graphing, but also a tool to visualize and prove geometric theorems and postulates.

Three Act Mathematics - TAM is a method developed by Dan Meyer that gives students access to mathematics problems involving visual, complex and real-world situations involving mathematics. There is a list of ready-made Algebra and Geometry lessons on the side tab.

National Council of Teachers of Mathematics Illuminations - NCTM Illuminations is a free collection of resources for mathematics educators. On the site there are several interactive simulations as well as lesson plans teachers can use.

PhET- PhET stands for Physics Education Technology and was developed by University of Colorado Boulder. Since its inception, PhET has expanded to multiple science disciplines and mathematics. This website is popular for science simulations and as a result, does not have as many mathematics simulations. PhET is primarily for high school-aged students, but does include activities for lower-level concepts like area and perimeter. When students work with these simulations they may initially get frustrated, because there are few directions. After some initial struggle, the relationship between concepts becomes intuitive.