This article includes the URL and description of 100 free web tools that can be used by all teachers. The tools are categorized into search engines, math and science, games, templates and lesson plans, and more.

An interactive applet and associated web page showing how the AAA similarity test works. Two similar triangles are shown that can be resized by dragging. The other triangle adjusts to remain similar and the angle-angle-angle elements are highlighted to show how they are involved in this test of similarity. (all three interior angles congruent). The web page describes all this and has links to other related pages. Applet can be enlarged to full screen size for use with a classroom projector. This resource is a component of the Math Open Reference interactive geometry reference book project at http://www.mathopenref.com.

Materials that make it easy for instructors to integrate data analytics into introductory accounting classes, including cases that are suitable for introductory accounting classes.

Some of the topics that this book addresses are: Vector spaces; finite-dimensional vector spaces; differential calculus; compactness and completeness; scalar product space; differential equations; multilenear functionals; integration; differentiable manifolds; integral calculus on manifolds; exterior calculus.

Note: this is a 57 MB PDF Document.

Algebra and Trigonometry provides a comprehensive exploration of algebraic principles and meets scope and sequence requirements for a typical introductory algebra and trigonometry course. The modular approach and the richness of content ensures that the book meets the needs of a variety of courses. Algebra and Trigonometry offers a wealth of examples with detailed, conceptual explanations, building a strong foundation in the material before asking students to apply what they’ve learned.

An interactive applet and associated web page that demonstrate the alternate exterior angles that are formed where a transversal crosses two lines. The applets shows the two possible pairs of angles alternating when in animation mode. By dragging the three lines, it can be seen that the angles are congruent only when the lines are parallel. When not in animated mode, there is a button that alternates the two pairs of angles. The text on the page discusses the properties of the angle pairs both in the parallel and non-parallel cases. Applet can be enlarged to full screen size for use with a classroom projector. This resource is a component of the Math Open Reference Interactive Geometry textbook project at http://www.mathopenref.com.

Use your knowledge of rectangle areas to calculate the missing measurement of these composite diagrams.
Find the value of the question marks in the diagrams. All of the shapes are rectangles but are not drawn to scale.

An interactive applet and associated web page that demonstrate the area of a circle. A circle is shown with a point on the circumference that can be dragged to resize the circle. As the circle is resized, the radius and the area computation is shown changing in real time. The radius and formula can be hidden for class discussion. Applet can be enlarged to full screen size for use with a classroom projector. This resource is a component of the Math Open Reference Interactive Geometry textbook project at http://www.mathopenref.com.

On this webpage you will find several open Mathematics textbooks along with supplemental material and a few lecture videos.
The purpose of these discipline specific pages is to display content that might be of interest to faculty who are considering adopting open educational resources for use in their classes. This list of content is by no means exhaustive. The nature of open educational resources is very collaborative and it is in that spirit that we encourage any comments about the content featured on this page or recommendations of content that are not already listed here.

An interactive applet and associated web page that demonstrate the circumference of a circle. The applet shows a circle with a radius line. The radius endpoints are draggable and the circle is resized accordingly. The formula relating radius to circumference is updated continually as you drag. Introduces the idea of Pi. The formula can be hidden for class discussion and estimation. See also the entries for circumference and diameter. See also entries for radius and diameter. Applet can be enlarged to full screen size for use with a classroom projector. This resource is a component of the Math Open Reference Interactive Geometry textbook project at http://www.mathopenref.com.

In this video, we use direction fields (drawn as quiver plots) to illustrate the numerical integration of differential equations. We include a heuristic example of how one might try to adapt step size by comparing different orders of approximation.

Discrete mathematics is applied in many areas including the physical, engineering, and increasingly, the social sciences. This online textbook, written by mathematics and information technology professors, is aimed at students of information technology, computer science, and applied mathematics. The focus is on applying discrete math techniques from the two broad component areas of discrete math, namely combinatorics or enumerative techniques, and graph theory.

This joint position statement of the National Association for the Education of Young Children (NAEYC) and the National Council

of Teachers of Mathematics (NCTM) highlights a set of principles for effective early math instruction.

This textbook is an introduction to college mathematics. It covers set theory, logic, numeration systems, probability, modular arithmetic, and measurement.

Introductory Statistics is intended for the one-semester introduction to statistics course for students who are not mathematics or engineering majors. It focuses on the interpretation of statistical results, especially in real world settings, and assumes that students have an understanding of intermediate algebra. In addition to end of section practice and homework sets, examples of each topic are explained step-by-step throughout the text and followed by a Try It problem that is designed as extra practice for students. This book also includes collaborative exercises and statistics labs designed to give students the opportunity to work together and explore key concepts. While the book has been built so that each chapter builds on the previous, it can be rearranged to accommodate any instructor’s particular needs.

An interactive applet that allows the user to graphically explore the properties of a linear functions. Specifically, it is designed to foster an intuitive understanding of the effects of changing the two coefficients in the function y=ax+b. The applet shows a large graph of a quadratic (ax + b) and has two slider controls, one each for the coefficients a and b. As the sliders are moved, the graph is redrawn in real time illustrating the effects of these variations. Applet can be enlarged to full screen size for use with a classroom projector. This resource is a component of the Math Open Reference Interactive Geometry textbook project at http://www.mathopenref.com.

This supplement is designed for MTH 243 at Portland Community College and is used in conjunction with OpenStax Statistics: https://openstax.org/details/introductory-statistics

This website will help you understand and apply the Understanding by Design (UbD) or Backward Design planning process to develop equitable units of math instruction. The UbD content will draw from the work done by Grant Wiggins and Jay McTighe, digitalcommons@trinity.edu., OER Commons, other resources and from Granite State College math and methods instructors.

We will examine each of the 3 main stages of unit planning and apply these concepts to planning math instruction for K-12 students.

Math in Society is a free, open textbook. This book is a survey of contemporary mathematical topics, most non-algebraic, appropriate for a college-level topics course for liberal arts majors. The text is designed so that most chapters are independent, allowing the instructor to choose a selection of topics to be covered. Emphasis is placed on the applicability of the mathematics. Core material for each topic is covered in the main text, with additional depth available through exploration exercises appropriate for in-class, group, or individual investigation. This book is appropriate for Math 107 (Washington State Community Colleges common course number).

This lesson describes the history and basic operation of the metric system as well as scientific notation. The simplicity of the metric system stems from the fact that there is only one unit of measurement (or base unit) for each type of quantity measured (length, weight, etc.).