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Activity
National Council of Teachers of Mathematics

The Math Forum: Ask Dr. Math: Compound Interest Rule of 70

For Students 9th - 10th
This page gives a brief explanation on how to compute compound interest.
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Unit Plan
National Council of Teachers of Mathematics

The Math Forum: Credit Card Calculations

For Students 9th - 10th
At this site Dr. Math answers a question about credit card balance payoffs. An advanced algebraic solution is offered.
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Activity
National Council of Teachers of Mathematics

The Math Forum: Ask Dr. Math: Stellated Dodecahedron

For Students 9th - 10th
This question and answer site provides information about stellated dodecahedrons, as well as several internet links to this topic.
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Activity
National Council of Teachers of Mathematics

The Math Forum: Ask Dr. Math: Volume of a Rectangular Solid

For Students 9th - 10th Standards
This question and answer site covers lateral area, total area, and volume of a rectangular solid.
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Unit Plan
National Council of Teachers of Mathematics

The Math Forum: Ask Dr. Math: Volume of a Cone

For Students 9th - 10th
This question and answer site poses a problem dealing with the volume of a partly filled cone.
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Unit Plan
National Council of Teachers of Mathematics

The Math Forum: Ask Dr. Math: Area, Volume of a Cone

For Students 9th - 10th Standards
This question and answer site gives the formulas for area and volume of a cone.
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Unit Plan
National Council of Teachers of Mathematics

The Math Forum: Ask Dr. Math: Apothem of a Hexagon

For Students 9th - 10th
This Q & A forum has a question answered on how to find the apothem of a hexagon.
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Handout
National Council of Teachers of Mathematics

The Math Forum: Drexel University Math Forum: Imaginary Numbers

For Students 9th - 10th Standards
Contains a short summary on imaginary numbers and several links to its related fields. Also provides several examples and explanations for understanding.
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Handout
National Council of Teachers of Mathematics

The Math Forum: Ask Dr. Math: De Moivre's Theorem Proof

For Students 9th - 10th
This Math Forum site contains a brief proof of De Moivre's Theorem ((cos(x)+isin(x))^n = cos(nx) + isin(nx)) Where n is an integer.
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Website
National Council of Teachers of Mathematics

The Math Forum: Ask Dr. Math: Congruence and Triangles

For Students 9th - 10th Standards
This site gives a very thorough explanation of how to tell if two triangles are congruent. Dr. Math explains why SSS, SAS, ASA determine that two triangles are congruent. The Dr. gives a few exercises for the reader to try then gives the...
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Activity
National Council of Teachers of Mathematics

The Math Forum: Ask Dr. Math: Determining if a Function Is Even or Odd

For Students 9th - 10th Standards
Dr. Math responds to a question about determining whether a function is even or odd. The Dr. explains the process and then does one example.
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Activity
National Council of Teachers of Mathematics

The Math Forum: K 12 Math Puzzles

For Students K - 1st
This site from the Math Forum of Drexel University provides a selection of math puzzles for grades K through 12 are found here. Types include: taking the numbers in the year 2004 and arriving at the numbers 1 through 100, using four 4s...
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Handout
National Council of Teachers of Mathematics

The Math Forum: The Cereal Box Problem

For Students 9th - 10th Standards
A cereal company is offering six different prizes in their boxes. How many boxes would you expect to have to purchase in order to collect all six prizes? Known as the Cereal Box Problem, this question is explored here. A solution is...
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Activity
National Council of Teachers of Mathematics

The Math Forum: Lattice Multiplication

For Students 3rd - 8th
Great web site that offers a detailed summary of how to multiply using the lattice multiplication method.
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Activity
National Council of Teachers of Mathematics

The Math Forum: Surface Area of a Sphere

For Students 9th - 10th
This site from Dr. Math at the Math Forum provides a concrete way to prove to students the formula for the surface area of a sphere.
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Unit Plan
National Council of Teachers of Mathematics

The Math Forum: Credit Card Debt

For Students 9th - 10th
This Ask Dr. Math site contains a question about how long it will take to repay a credit card debt at a particular APR and particular amount per month.
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Website
National Council of Teachers of Mathematics

The Math Forum: Ask Dr. Math: Pi and the Area of Circles

For Students 9th - 10th Standards
Contains a question pertaining to finding the area of a circle.
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Activity
National Council of Teachers of Mathematics

The Math Forum: Plane Figure

For Students 9th - 10th
This site provides a definition for plane figure (at the top of the page) and a few examples.
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Handout
National Council of Teachers of Mathematics

The Math Forum: Restrictions on Roots

For Students 9th - 10th Standards
A question is asked if there are any restrictions on "n" when talking about the nth root of a number.
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Activity
National Council of Teachers of Mathematics

The Math Forum: Number Tricks

For Students 7th - 9th
This site from the Drexel University gives a few number tricks and asks for you to make a number trick of your own, it really is not difficult, yet to the non-math oriented seems like magic.
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Activity
National Council of Teachers of Mathematics

The Math Forum: Ask Dr. Math: Cramer's Rule in Action

For Students 9th - 10th
This site provides a specific example of Cramer's Rule. The site does not explain why Cramer's Rule works, yet does a fair job of expressing the method to reach the answers.
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Website
National Council of Teachers of Mathematics

The Math Forum: Ask Dr. Math: Volume of a Triangular Tank

For Students 9th - 10th
This question and answer site solves a volume problem for a triangular tank.
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Unit Plan
National Council of Teachers of Mathematics

The Math Forum: Ask Dr. Math: Is a Sphere 2 D or 3 D?

For Students 9th - 10th
Do you think you know weather a sphere is two dimensional or three dimensional? Read this question posed to Doctor Math, very interesting.
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Unit Plan
National Council of Teachers of Mathematics

The Math Forum: Ask Dr. Math: Sphere Eversion

For Students 9th - 10th
This question and answer site provides links to sites that show how to mathematically turn a sphere inside out.