This award winning math site is searchable by grade level (6-8, 9-10, 11-12), course content and activities. It encourages:
Active Learning
- The unique content format makes learning more interactive than ever before. Students can explore, discover and actively engage in problem solving and creativity.
Personalization
- The content can seamlessly adapt to different students, allowing everyone to achieve mastery. A virtual personal tutor gives real-time hints and encouragement.
Storytelling
- Every course has a captivating narrative and is full of colourful illustrations. Discover all the real-life applications of mathematics, and why it is incredibly beautiful.

Just a few topics include:
- Virtual manipulatives (including Canadian money)
- multiplication flash cards
- Fractals
- timeline of mathematics
- graph theory
- Pascal's triangle
- Factris
- Fibonacci
- circles and pi
- origami
- Platonic Solids
- Symmetry
- Probability
- Cylinders

Discover Mathigon, the Mathematical Playground. Learning mathematics has never been so interactive and fun!
Check out:
Polypad - Virtual manipulatives, dynamic geometry, graph plotting, data science and more: explore the ultimate mathematical playground!
Multiplication by Heart - These beautiful flash cards use spaced repetition to teach multiplication facts. Achieve fluency with just five minutes of practice per day!
Activities - A selection of our favourite mathematical puzzles and problems. Most are simple to understand, but the solutions require clever and unconventional thinking.
Factris - A fun game that teaches about simple arithmetic
Course Library - Mathigon's innovative courses cover everything from fractions and trigonometry to graph theory, cryptography, prime numbers and fractals.
Puzzles, Activities and Lesson Plans - Student Explorations/Activities for students to complete ; Fully developed lessons plans ; Ready to play puzzles and games ; Teaching ideas using Polypad to explore new ideas; Tutorials - Learn how to use Polypad
Almanac of Interesting Numbers
And much more!

Math is Fun is a free website offering mini explanations of math topics from all levels, including elementary to high school. It also features tons of games and puzzles to explore. It also includes an illustrated math dictionary with interactive activities for the students to explore and deepen mathematical understanding.

Find resources for different age levels in the following areas:
Pre-K to 2
- Numbers
- Algebra
- Geometry
- Data
- Measurement
- Money

3 to 6
- Numbers
- Algebra
- Geometry
- Data
- Measurement
- Money

7 to 9
- Numbers
- Algebra
- Geometry
- Data
- Measurement
- Money

10 upwards
- Numbers
- Algebra
- Geometry
- Data
- Measurement
- Calculus

A free web based math / scientific calculator specially designed for the education environment. It operates in a very similar way to the popular school calculators and so does not need re-learning. The calculator can be blown up to full screen size, making it a useful teaching tool in a classroom setting with a projector. Functions: sin, cos, tan, sin-1, cos-1,tan-1 square root, log10, loge, power of ten, squared, ex Constants: pi, e, root 2 This resource is a component of the Math Open Reference Interactive Geometry textbook project at http://www.mathopenref.com.

This goal of this task is to give students familiarity using the formula for the area of a circle while also addressing measurement error.

A web page and interactive applet illustrating the medians of a triangle. The applet shows a triangle where the user can drag the vertices to reshape it. As the triangle is being reshaped, the user can see the three median lines tracking the changes, and observe that that all three always intersect at a point inside the triangle. The page text explains that this point of intersection is also the centroid of the triangle, and explains how to determine the location of the medians. 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.

An interactive applet and associated web page that demonstrate the midpoint of a line segment. The applet shows a line segment that can be resized and moved using draggable endpoints. The applet always shows the midpoint of the changing line segment. 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 classroom task gives students the opportunity to prove a surprising fact about quadrilaterals: that if we join the midpoints of an arbitrary quadrilateral to form a new quadrilateral, then the new quadrilateral is a parallelogram, even if the original quadrilateral was not.

An interactive applet and associated web page that demonstrate how to find the midpoint of a line segment when the coordinates of the endpoints are given. The applet has two points on a Cartesian plane. As the user drags either point it continuously recalculates the midpoint of the line segment defined by them. The midpoint is shown both on the plane and as a continuously changing formula. The grid, axis pointers and coordinates can be turned on and off. The midpoint calculation can be turned off to permit class exercises and then turned back on the verify the answers. The applet can be printed as it appears on the screen to make handouts. The web page has a full description of the method for finding the midpoint, a worked example and has links to other pages relating to coordinate geometry. 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 is a reasonably direct task aimed at having students use previously-derived results to learn new facts about parallelograms, as opposed to deriving them from first principles. The solution provided (among other possibilities) uses the SAS trial congruence theorem, and the fact that opposite sides of parallelograms are congruent.

The purpose of this task is to engage students in an open-ended modeling task that uses similarity of right triangles, and also requires the use of technology.

(Nota: Esta es una traducción de un recurso educativo abierto creado por el Departamento de Educación del Estado de Nueva York (NYSED) como parte del proyecto "EngageNY" en 2013. Aunque el recurso real fue traducido por personas, la siguiente descripción se tradujo del inglés original usando Google Translate para ayudar a los usuarios potenciales a decidir si se adapta a sus necesidades y puede contener errores gramaticales o lingüísticos. La descripción original en inglés también se proporciona a continuación.)

Este módulo final del año de 40 días ofrece a los estudiantes una práctica intensiva con problemas de palabras, así como experiencias prácticas de investigación con geometría y perímetro. El módulo comienza con la resolución de problemas de palabras de uno y dos pasos basados ​​en una variedad de temas estudiados durante todo el año, utilizando las cuatro operaciones. A continuación, los estudiantes exploran la geometría. Estudiantes Tessellate para la experiencia de la geometría de puente con el estudio del perímetro. Las parcelas de línea, familiares del Módulo 6, ayudan a los estudiantes a sacar conclusiones sobre las mediciones de perímetro y área. Los estudiantes resuelven problemas de palabras que involucran área y perímetro utilizando las cuatro operaciones. El módulo concluye con un conjunto de lecciones atractivas que revisan brevemente los conceptos fundamentales de grado 3 de fracciones, multiplicación y división.

Encuentre el resto de los recursos matemáticos de Engageny en https://archive.org/details/engageny-mathematics.

English Description:
This 40-day final module of the year offers students intensive practice with word problems, as well as hands-on investigation experiences with geometry and perimeter.  The module begins with solving one- and two-step word problems based on a variety of topics studied throughout the year, using all four operations.  Next students explore geometry.  Students tessellate to bridge geometry experience with the study of perimeter.  Line plots, familiar from Module 6, help students draw conclusions about perimeter and area measurements.  Students solve word problems involving area and perimeter using all four operations.  The module concludes with a set of engaging lessons that briefly review the fundamental Grade 3 concepts of fractions, multiplication, and division.

Find the rest of the EngageNY Mathematics resources at https://archive.org/details/engageny-mathematics.

In this lesson, students will learn that math is important in navigation and engineering. Ancient land and sea navigators started with the most basic of navigation equations (Speed x Time = Distance). Today, navigational satellites use equations that take into account the relative effects of space and time. However, even these high-tech wonders cannot be built without pure and simple math concepts basic geometry and trigonometry that have been used for thousands of years. In this lesson, these basic concepts are discussed and illustrated in the associated activities.

This task applies geometric concepts, namely properties of tangents to circles and of right triangles, in a modeling situation. The key geometric point in this task is to recognize that the line of sight from the mountain top towards the horizon is tangent to the earth. We can then use a right triangle where one leg is tangent to a circle and the other leg is the radius of the circle to investigate this situation.

A web page and interactive applet illustrating the properties of a nonagon (9 sided polygon). The applet shows a nonagon where the user can drag any vertex to reshape it. User can see that the interior and exterior angles are constant in a regular nonagon, but vary in an irregular version. Controls allow the display or hiding of the diagonals, and triangles within the nonagon. The web page lists the properties of a nonagon including interior angles, exterior angles, sum of exterior angles, area, number of diagonals and number of internal triangles. Links to pages with generalized properties of all polygons. 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.

An interactive applet and associated web page that demonstrate obtuse angles (those between 90 and 180 deg). The applet presents an angle (initially obtuse) that the user can adjust by dragging the end points of the line segments forming the angle. As it changes it shows the angle measure and a message that indicate which type of angle it is. There a software 'detents' that make it easy capture exact angles such as 90 degrees and 180 degrees The message and angle measures can be turned off to facilitate classroom discussion. The text on the page has links to other pages defining each angle type in depth. 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.

An interactive applet and associated web page that demonstrate the three types of triangle: acute, obtuse and right. The applet shows a triangle that is initially obtuse (one angle greater than 90 degrees) which the user can reshape by dragging any vertex. There is a message changes in real time while the triangle is being dragged that tells if the triangle is an acute, right or obtuse triangle and gives the reason why. By experimenting with the triangle student can develop an intuitive sense of the difference between these three classes of triangle. 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.

A web page and interactive applet illustrating the properties of a octagon (8 sided polygon). The applet shows an octagon where the user can drag any vertex to reshape it. User can see that the interior and exterior angles are constant in a regular octagon, but vary in an irregular version. Controls allow the display or hiding of the diagonals, and triangles within the octagon. The web page lists the properties of an octagon including interior angles, exterior angles, sum of exterior angles, area, number of diagonals and number of internal triangles. Links to pages with generalized properties of all polygons. 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.

The lesson begins by introducing Olympics as the unit theme. The purpose of this lesson is to introduce students to the techniques of engineering problem solving. Specific techniques covered in the lesson include brainstorming and the engineering design process. The importance of thinking out of the box is also stressed to show that while some tasks seem impossible, they can be done. This introduction includes a discussion of the engineering required to build grand, often complex, Olympic event centers.

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