A web page and interactive applet illustrating Thales Theorem (the diameter of a circle always subtends a right angle to any point on the circumference). The applet shows a circle where the user can rotate the diameter and a move a point on the circumference. The applet continuously shows the resulting right triangle, demonstrating that the theorem holds no matter how the points are moved around. Text on the page defines the theorem and relates it to other geometric entities. 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.

Simple math test activities for teachers and students, from beginning math operations to calculus. You set the skill level, how many problems, and time limit. A report, which tallies right and wrong answers, is provided after each quiz. Grades: 3–12; cost: Free

Third-grade math instruction is focused on the following areas: developing an understanding of multiplication and division and strategies for multiplication and division within 100; developing an understanding of fractions, especially unit fractions (fractions with numerator 1); developing an understanding of the structure of rectangular arrays and of area; describing and analyzing two-dimensional shapes.

The best way to ensure your students fully grasp the math concepts they'll need to successfully progress in their education is to practice as much as possible. The worksheets, puzzles, games, and other resources available here are the perfect solution for parents and teachers who want to provide their third graders with the tools they need to understand and excel in third-grade math.

Jen Saul combines think time, partner discussions, and an emphasis on students' personal strategies to build confidence through mental math. Students use and discuss the strategies of "decomposing," "splitting," and "jumps of ten."

Families can take math estimation challenges in a wide variety of fun ways.

Tiny Polka Dot is the playful way for children ages 3 – 8 and up to fall in love with numbers. It has eye-catching, colorful cards and 16 easy-to-learn games, Tiny Polka Dot is built to grow with your child, teaching critical skills in counting, arithmetic, and logic along the way.

This downloadable file contains everything you need to print out a Tiny Polka Dot starter deck. It
contains the 3 core suits of the game, which should be enough to get kids started with all
the games and puzzles.

This is a printer-friendly version, so it should go easier on your printer ink.

This file also includes instructions, rule cards, and the Guide for Grownups,

"Tomatosphere™ offre une excellente opportunité pour permettre à vos élèves de penser et agir comme des scientifiques tout en pratiquant leurs compétences en recherche et en développant leur compréhension de la nature de la science et du concept d'une expérience équitable.

Au printemps, les salles de classe participantes reçoivent deux paquets de graines de tomates. Un paquet contient des graines envoyées dans l'espace ou traitées dans des conditions simulées d'espace. L'autre contient des graines "témoins" non traitées. Les élèves plantent les graines et réalisent des expériences pour explorer les effets de l'environnement spatial sur la germination des tomates. Grâce à Tomatosphere™, les élèves apprennent comment mener une expérience scientifique et comparent le nombre de graines qui germent pour les deux groupes de graines.

Pendant le programme Tomatosphere™, les élèves étudient comment fournir aux missions d'exploration spatiale les besoins en support de vie tels que la nourriture, l'eau, l'oxygène et un moyen de consommer le dioxyde de carbone expiré par les astronautes, tout en discutant des nombreux problèmes et recherches liés à l'exploration spatiale.

Les enseignants peuvent étendre l'Investigation de base sur les graines Tomatosphere™ en la reliant à des études sur les plantes, l'espace, la nutrition, les mathématiques ou l'environnement, en fonction du niveau et du programme d'études."

Tous droits réservés

Students in Mathematics 6/7/8 work in mixed-grade groups to determine a “Top 5” list of concepts from the course based on provided criteria developed over the course of the year. Students choose a format in which to share their “Top 5” including rationale for why each concept connects to mathematics outside of the classroom. Ultimately, students present their conclusions in an attempt to convince the panel that their “Top 5” is the most deserving of entering the Mathematics Hall of Fame. I decided to use mixed-grade groups for this project in an attempt to encourage more rich conversation as students need to explain concepts in order to convince their peers of their importance. The timing of this project at the end of the year also allows the work to serve as review for final written evaluations.

Toy Theater playfully teaches conceptual foundations with online interactive games and activities that have real educational value. Find resources for math, reading, art, music, puzzles and games.

Lamarr Oksasikewiyin provides traditional games for developing number sense with early learners. Lamarr created a series of Facebook videos with a focus on number games, number concepts, and traditional ways of knowing. A Facebook account is not required to view.

An interactive applet and associated web page that demonstrate the transversal, a line that crosses two other (usually parallel) lines. The applet shows two lines that are initially parallel, and a transversal line. All eight angles thus formed are shown. As you drag the transversal end points, you can see that the angles form congruent, supplementary and complementary sets. If you move one of the parallel lines to make it non-parallel, you can see that these angles lose some of their relationship with each other. 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 showing the definition and properties of a trapezoid. The applet shows a trapezoid where the user can drag any vertex. The other points then move in such a way that the figure remains a trapezoid at all times. A control to hide the details allows a classroom discussion where students can try to infer what the properties are as it is reshaped by the discussion leader. Text on the page has the formal definition and properties of the trapezoid with links to related pages. A companion page is http://www.mathopenref.com/trapezoidarea.html showing the ways to calculate the area of a trapezoid 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 show the definition and properties of a trapezoid in coordinate geometry. The applet has a trapezoid with draggable vertices. As the user re-sizes the trapezoid the applet continuously recalculates its altitude and median from the vertex coordinates. The trapezoid can be rotated on the plane to show the more complex cases. The grid, coordinates and calculations can be turned on and off for class problem solving. The applet can be printed in the state it appears on the screen to make handouts. The web page has a full definition of a trapezoid when the coordinates of the points defining it are known, 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.

An interactive applet and associated web page showing how to find the area and perimeter of a trapezoid from the coordinates of its vertices. The trapezoid can be either parallel to the axes or rotated. The grid and coordinates can be turned on and off. The area and perimeter 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 determining area and perimeter, 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.

An interactive applet and associated web page that demonstrate the median line of a trapezoid (line linking midpoints of non-parallel sides). The applet shows a trapezoid with all vertices draggable. As you drag any vertex, the figure changes to remain trapezoid, and the median line id continually repositioned to remain correct. It can be seen visually that the median remains parallel to the bases and a formula shows that its length is the average of the bases. 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 introduce the concept of a triangle. The applet shows a triangle where the user can drag the vertices to reshape it. As it is being dragged a base and altitude are shown continuously changing. Demonstrates that the altitude may require the base to be extended. The text on the page lists the properties of a triangle and lists the various triangle types, with links to a definition of each. 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 applet shows a triangle which the user can resize by dragging any of its vertices. It shows the three perpendicular bisectors of the sides and the point where they intersect - the circumcenter. These track the changes in the triangle in real time. It shows that the circumcenter may lie outside the triangle. The associated web page describes the properties of the circumcenter and points out that it the center of the triangle's circumcircle. 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 demonstrating the concept of the incenter of a triangle. The applet shows a triangle where the user can drag the vertices around. The incenter and the angle bisector lines that generate it are continuously moved as the user drags the vertices. By experimentation the user can observe that the incenter always remains inside the triangle. The page text explains the definition of the incenter and how to find it. It describes how the incenter is also the center of the incircle of the triangle with a link to that page http://www.mathopenref.com/triangleincenter.html 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 demonstrating the concept of the centroid of a triangle. The applet shows a triangle where the user can drag the vertices around. The centroid and the median lines that generate it are continuously moved as the user drags the vertices. By experimentation the user can observe that the centroid always remains inside the triangle. The page text explains the definition of the centroid and how to find it. It also shows that the centroid is the center of gravity of the 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.

An interactive applet and associated web page that demonstrate the properties of the circumcircle of a triangle. The applet shows a triangle where the user can drag the vertices to reshape it. The circumcircle (the circle that passes through all vertices) is continuously updated as the triangle is resized. The center of the circle (circumcenter) is shown along with the three side bisectors that define it. 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.