From Wolfram MathWorld. The Platonic solids, also called the regular solids or regular polyhedra, are convex polyhedra with equivalent faces composed of congruent convex regular polygons.

There are exactly five such solids (Steinhaus 1999, pp. 252-256): the cube, dodecahedron, icosahedron, octahedron, and tetrahedron, as was proved by Euclid in the last proposition of the Elements. The Platonic solids are sometimes also called "cosmic figures" (Cromwell 1997), although this term is sometimes used to refer collectively to both the Platonic solids and Kepler-Poinsot solids (Coxeter 1973). The Platonic solids were known to the ancient Greeks, and were described by Plato in his Timaeus ca. 350 BC.

In this work, Plato equated the tetrahedron with the "element" fire, the cube with earth, the icosahedron with water, the octahedron with air, and the dodecahedron with the stuff of which the constellations and heavens were made (Cromwell 1997). Wang tile - Wikipedia. This set of 11 Wang tiles will tile the plane but only aperiodically.

Example of Wang tessellation with 13 tiles. The basic question about a set of Wang tiles is whether it can tile the plane or not, i.e., whether an entire infinite plane can be filled this way. The next question is whether this can be done in a periodic pattern. Domino problem[edit] Best Websites for Teaching Math: More Than 50 Resources! We recently sent the call out on our Teacher HELPLINE!

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Divisibility criteria. Equation editors. Graphers. Limits. Sets Theory. Solvers. Relazione di Stiefel. Nuova pagina 1. The On-Line Encyclopedia of Integer Sequences® (OEIS®) The Clay Mathematics Institute. ZbMATH - the first resource for mathematics. Angles on Google Drawings.webm. Libro di testo. TENSORI fatti facili con PROBLEMI:Amazon:Libri. Semester 1 - Algebra. Flippedmath.com - Home. Music Math Harmony. A Random Math Fun Fact! From the Fun Fact files, here is a Random Fun Fact, at the Advanced level: The traditional proof that the square root of 2 is irrational (attributed to Pythagoras) depends on understanding facts about the divisibility of the integers.

(It is often covered in calculus courses and begins by assuming Sqrt[2]=x/y where x/y is in smallest terms, then concludes that both x and y are even, a contradiction. See the Hardy and Wright reference.) Odd Numbers in Pascal's Triangle. Pascal's Triangle has many surprising patterns and properties.

For instance, we can ask: "how many odd numbers are in row N of Pascal's Triangle? " For rows 0, 1, ..., 20, we count: row N: 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 odd #s: 1 2 2 4 2 4 4 8 2 4 04 08 04 08 08 16 02 04 04 08 04. Sums of Two Squares Ways. In the Fun Fact Sums of Two Squares, we've seen which numbers can be written as the sum of two squares.

For instance, 11 cannot, but 13 can (as 32+22). A related question, with a surprising answer, is: on average, how many ways can a number can be written as the sum of two squares? We should clarify what we mean by average. Let W(N) is the number of ways to write N as the sum of two squares. Fibonacci GCD's, please. Fibonacci numbers exhibit striking patterns.

Here's one that may not be so obvious, but is striking when you see it. Recall the Fibonacci numbers: n: 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14,... Numberphile - Videos about Numbers and Stuff. Mangahigh.com - Play maths, love maths.

Physics & Maths Tutor. Learn Math. Algebra - Home. IB Maths Resources from British International School Phuket. Watch free videos in math, science, SAT and ACT - Brightstorm. Math. The Harmonious Mathematics of Music. According to legend, the Ancient Greek Pythagoras was once walking on the streets of Samos, when the sounds of blacksmiths’ hammering suddenly gave him an epiphany.

Pythagoras rushed into the shop and, as he analyzed mathematically the shapes of the blacksmiths’ hammers, he laid the foundations of music that today’s Rihanna, Shakira and others are building upon. Wait a minute… Are you talking about the guy from the Pythagorean theorem? I am. And despite what you’ve learned at school, this Pythagorean theorem is absolutely not Pythagoras’ greatest idea — most notably because he probably wasn’t even the one who came up with the Pythagorean theorem.

Collaborative Mathematics - Home. NLVM Geometry Manipulatives. Algebra Tiles - Working with Algebra Tiles. BASE Cinque light - Appunti di Matematica ricreativa. Archivio prove invalsi. From Wolfram MathWorld. A special function which is given by the logarithmic derivative of the gamma function (or, depending on the definition, the logarithmic derivative of the factorial).

Home. Maths and English Practice. Isometric Drawing Tool. The Great Pi Conspiracy: Are We Using the Wrong Pi? My understanding of pi is that it is 3.141 with endless number.

In other words, pi is a set of numbers that has no ending. It is infinite just like a circle. Because it is infinite, it can not be multiplied or divided with any number and come to any conclusion. You can not calculate a mathematical formula and come to a solid conclusion unless you make the number whole or round it down to numbers that can be divided. Practice Trigonometry. Good Stuff. Maths Resources. Free Maths Resources, Worksheets and Games. Learning and Teaching. Pbrucemaths.weebly.com - Home. My All Time Favorite Middle School Math Lessons. Artful Maths - Home. Geometry Rap Songs - Learn Terms, Shapes & Formulas - Flocabulary. Online math practice and lessons.

Math Help for Parents And Their Kids. KBruch. Description KBruch is a small program to practice calculating with fractions. Therefore 4 different exercises are offered. Exercise Fraction Task - in this exercise you have to solve a given fraction task. Matemáticas. Math Games - HOODA MATH - over 100 Math Games. Web 2.0 Tools for Math Educators. By Laura Turner This is a continuing series on Web2.0 and other web-based tools for educators. This information is specific to math educators, but there is some crossover into science. Math educators will find a large number of useable interactive companion web sites for the teaching of math concepts and skills. 3Dvinci 3D design is a great motivational and instructional tool. It exercises both left-brain and right-brain skills, and appeals to students of all abilities.

Algebasics This site contains a variety of interactive Algebra help/ problems/activities. Create A Graph. GridOmatic, print your own graph paper. Return to Bad pictures ? Click here GridOmatic, print your own graph paper, imperial or metric at any scale The only purpose of this little tool is to print graph paper, either as millimetric (with 10th divisions) or imperial (with 8th divisions).

A laser or inkjet printer is capable of printing paper of a very high quality, and as a bonus you can adjust the scale, to enlarge/reduce the grid and suit your needs of any scale drawing. I use those papers all the time to draw the things I will machine. It is a single executable that run under Windows, without specific installation. GridOmatic.exe (268 KB) for ZIP challenged people, here's the strait executable Windows program. At this place you just choose to run it on your computer. Illustrated Mathematics Dictionary. Mathonopoly: si gioca a Monopoli... con la matematica! A085471. CIDI - Centro di Iniziativa Democratica degli Insegnanti. Free Math Worksheets.

1001 Math Problems. Equazioni reciproche. Verifiche di matematica.