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Website
National Council of Teachers of Mathematics

The Math Forum: Ask Dr. Math: Triangle Inequality

For Students 9th - 10th
Dr. Math gives a hint of how to prove the triangle inequality theorem when answering a question posed about proving an absolute value problem using the triangle inequality theorem.
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Activity
National Council of Teachers of Mathematics

The Math Forum: Basic Divisibility Rules

For Students 9th - 10th
This site offers a short quick reference list of divisibility rules with links to the explanations
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Unit Plan
National Council of Teachers of Mathematics

The Math Forum: Ask Dr. Math: Compound Inequality (No Intersection)

For Students 9th - 10th
"Dr. Math" responds to a student question about possible solutions to compound inequality problems, the Dr. addresses the possiblity of no intersections for a conjunctive answer.
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Unit Plan
National Council of Teachers of Mathematics

The Math Forum: Ask Dr. Math: Solving Inequalities and Absolute Values

For Students 9th - 10th Standards
"Dr. Math" provides an indepth explanation in solving inequalities that involve absolute value. The indepth explanation revolves around a specific problem sent in by a student. This site includes a graph of the absolute value problem.
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Unit Plan
National Council of Teachers of Mathematics

The Math Forum: Fractions: Middle School Lessons & Materials

For Teachers 6th - 8th
A large archive of sites to help teachers with lesson plans and materials for teaching fractions. Geared toward middle school students and teachers.
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Activity
National Council of Teachers of Mathematics

The Math Forum: Pascal's Triangle

For Students 9th - 10th
Students can find all sorts of number patterns in Pascal's Triangle.
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Handout
National Council of Teachers of Mathematics

The Math Forum: Ask Dr. Math: Equation of a Sphere

For Students 9th - 10th
Learn about how many points determine a unique sphere and how many points are needed to create a family of spheres. Dr. Rob works out the equation of a family of spheres given three points and then the equation of a unique sphere can be...
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Unit Plan
National Council of Teachers of Mathematics

The Math Forum: Ask Dr. Math: Distance From a Point to a Plane

For Students 9th - 10th
Use this site to findout how to find the distance from a point to a plane.
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Website
National Council of Teachers of Mathematics

The Math Forum: Ask Dr. Math Alternate Exterior Angles

For Students 9th - 10th
Dr. Math at the Math Forum offers a way of remembering alternate exterior and alternate interior angles by looking at the words and realize what they say and apply it to the picture.
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Website
National Council of Teachers of Mathematics

The Math Forum: Ask Dr. Math: Intersecting Angles

For Students 6th - 8th
This site from The Math Forum of Drexel University provides a question posed by a students with a response. The question involves the points of intersection of two intersecting angles.
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Handout
National Council of Teachers of Mathematics

The Math Forum: Volume

For Students 9th - 10th Standards
At this site from the Math Forum, Dr. Math explains the concept of volume using area as the base of information. The explanation includes some examples and is worth using for information on the subject.
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Activity
National Council of Teachers of Mathematics

The Math Forum: K 12 Math Problems, Puzzles, Tips & Tricks

For Students K - 1st
At this site us these tips & tricks to help students become better mental mathematicians.
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Unit Plan
National Council of Teachers of Mathematics

The Math Forum: Cylinder Formulas

For Students 9th - 10th
This site from the Math Forum defines both a circular cylinder and a right circular cylinder. Pictures of each are provided. Formulas are provided.
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Website
National Council of Teachers of Mathematics

The Math Forum: Geometry Discussion Board

For Students 9th - 10th
Math Forum provides a discussion board for geometry topics. The geometry topics are for pre college topics. This site may be found enjoyable for those who like to think about math topics at times other than school.
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Lesson Plan
National Council of Teachers of Mathematics

The Math Forum: Bricks Activity, Teacher Lesson Plan

For Teachers 6th - 8th
Builders of brick walls need to be especially aware of fault lines which can easily lead to the collapse of the wall. Students are challenged, here, to use polyminoes to design patterns for brick walls which do not contain fault lines....
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Unit Plan
National Council of Teachers of Mathematics

The Math Forum: Ask Dr. Math: Equation for Undefined Slope

For Students 9th - 10th Standards
This site gives the equation for a vertical line which passes through 8 on the x axis. The Dr. explains why the equation is what it is by giving a more general equation for a line than y = mx + b.
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Unit Plan
National Council of Teachers of Mathematics

The Math Forum: Ask Dr. Math: Line Problems

For Students 9th - 10th Standards
This site answers many general questions about linear equations and their graphs. A student posed several questions to Dr. Math regarding lines and their equations. Question number 4 is about the equation of a horizontal line and Dr....
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Activity
National Council of Teachers of Mathematics

The Math Forum: Ask Dr. Math: Quadratic Function (Changing Coefficients)

For Students 9th - 10th Standards
The Dr. gives information about a method for deciding how changing the coefficients of a quadratic function affects a graph. The page also leaves some questions for the reader to ponder.
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Activity
National Council of Teachers of Mathematics

The Math Forum: Ask Dr. Math: Faq: Closure

For Students 9th - 10th
This site explains closure and has a link to a response from Dr. math regarding this topic. The site explains why the real numbers are closed under the operation of multiplication. The site gives an example of an operation which the real...
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Handout
National Council of Teachers of Mathematics

The Math Forum: Ask Dr. Math: Rhombus

For Students 9th - 10th Standards
This is a very brief look at the rhombus, which is a quadrilateral shape with four equal sides. Features include a JavaSketchpad that allows you to manipulate the shape.
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Handout
National Council of Teachers of Mathematics

The Math Forum: Geometry Through Art: Inscribed Triangles

For Students 9th - 10th
This resource contains examples of triangles inscribed in circles to form art.
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Activity
National Council of Teachers of Mathematics

The Math Forum: Polyhedra Nets Paper

For Students 9th - 10th Standards
Contains six examples of polyhedra nets (cube, tetrahedron, octahedron, dodecahedron, icosahedron, cubosctahedron).
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Unit Plan
National Council of Teachers of Mathematics

The Math Forum: The Art of Oriental Carpets

For Students 9th - 10th
This site from the Math Forum of Drexel University gives an idea of how symmetry and pattern is used in oriental carpets. Links are provided throughout for additional information on related subjects.
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Website
National Council of Teachers of Mathematics

The Math Forum: Similarity and Congruence

For Students 9th - 10th
This site from Dr. Math at the Math Forum provides a collection of problems and exercises that require knowledge of the relations between similar or congruent shapes. Solutions are provided.