This video tutorial investigates cross sections of geometric solids and provides examples of the drawings. Students can check their understanding with an assessment. [4:21]

This site provides an explanation of mathematical proofs. It also has links to different types of proofs.

Carol Hurst provides this sample chapter from "Picturing Math." Gathering data is a frequent part of solving problems and satisfying curiosity, which includes working with graphs and using mathematical tools such as averaging and other computations.

Very complete explanation of mean, standard deviation, etc. including an online calcluator for these statistics.

Students learn about the mathematical characteristics and reflective property of ellipses by building their own elliptical-shaped pool tables. After a slide presentation introduction to ellipses, student “engineering teams” follow the steps of the engineering design process to develop prototypes, which they research, plan, sketch, build, test, refine, and then demonstrate, compare and share with the class. Using these tables as models to explore the geometric shape of ellipses, they experience how particles rebound off the curved ellipse sides and what happens if particles travel through the foci. They learn that if a particle travels through one focal point, then it will travel through the second focal point regardless of what direction the particle travels.

Demonstrates how to systematically find all the possible outcomes of rolling two dice in order to determine the probability of rolling doubles. [5:15]

Khan Academy learning modules include a Community space where users can ask questions and seek help from community members. Educators should consult with their Technology administrators to determine the use of Khan Academy learning modules in their classroom. Please review materials from external sites before sharing with students.

This Univ. of St. Andrews site provides information on "the father of algebra," Diophantus.

This video lesson demonstrates long division of a two-digit number by a one-digit number, where the answer will contain a repeating decimal. It is 1 of 10 in the series titled "Dividing Two-Digit Numbers by One-Digit Numbers Repeating." Includes short multiple-choice quiz. [2:07]

This video demonstrates division of two-digit numbers by two- or three-digit numbers. This lesson is 1 of 19 in the series titled "Dividing Two-Digit Numbers by Two or Three-Digit Numbers." Includes short multiple-choice quiz. [4:19]

Divide two whole numbers to get a quotient with a decimal. Students receive immediate feedback and have the opportunity to try questions repeatedly, watch a video or receive hints.

Khan Academy learning modules include a Community space where users can ask questions and seek help from community members. Educators should consult with their Technology administrators to determine the use of Khan Academy learning modules in their classroom. Please review materials from external sites before sharing with students.

Demonstrates how to follow written directions for drawing a trapezoid on a coordinate plane. [2:41]

Khan Academy learning modules include a Community space where users can ask questions and seek help from community members. Educators should consult with their Technology administrators to determine the use of Khan Academy learning modules in their classroom. Please review materials from external sites before sharing with students.

Given an inverse trigonometric function, this lesson demonstrates how it can be evaluated for a particular value. It is 6 of 7 in the series titled "Evaluating an Inverse Function." [3:26]

This lesson explains that evaluating a function involves finding the output value, given the input value. It is 1 of 5 in the series titled "Evaluation of a Function." Includes a short quiz. [2:05]

Sal gives a "trick" for expanding large powers of binomials, without using Pascal's triangle. [4:58]

Khan Academy learning modules include a Community space where users can ask questions and seek help from community members. Educators should consult with their Technology administrators to determine the use of Khan Academy learning modules in their classroom. Please review materials from external sites before sharing with students.

Practice factoring polynomials with a common factor.

Khan Academy learning modules include a Community space where users can ask questions and seek help from community members. Educators should consult with their Technology administrators to determine the use of Khan Academy learning modules in their classroom. Please review materials from external sites before sharing with students.

Practice applying the distributive property to factor numerical expressions (no variables). Students receive immediate feedback and have the opportunity to try questions repeatedly, watch a video or receive hints.

Khan Academy learning modules include a Community space where users can ask questions and seek help from community members. Educators should consult with their Technology administrators to determine the use of Khan Academy learning modules in their classroom. Please review materials from external sites before sharing with students.

This lesson derives the equation for a circle starting from the distance formula. It is 1 of 9 in the series titled "Finding the Equation of a Circle." [3:58]

This lesson demonstrates how to find the probability of two independent events occurring. It is 5 of 5 in the series titled "Finding the Probability of Two Independent Events." [4:07]

The University of St. Andrews offers this iography of Francois Viete. Many links are provided for more information.

Explore free math apps and websites that will engage students in grades K-8. Obtain practical tips and best practices to implement the resources.