This article includes the URL and description of 100 free web tools that can be used by all teachers. The tools are categorized into search engines, math and science, games, templates and lesson plans, and more.

Rubric Element 1.10 Teachers implement routines and procedures for efficiently guiding students through digital and non-digital work time.

An interactive applet and associated web page that demonstrate the properties of a 30-60-90 triangle. The applet shows a right triangle that can be resized by dragging any vertex. As it is dragged, the remaining vertices change so that the triangle's angles remain 30 degrees, 60 degrees and 90 degrees The text on the page points out that the sides of a 30-60-90 triangle are always in the ratio of 1 : 2 : root 3 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 a 3:4:5 triangle - one of the Pythagorean triples. The applet shows a right triangle that can be resized by dragging any vertex. As it is dragged, the remaining vertices change so that the triangle's side remain in the ration 3:4:5. The text on the page has an example of how the triangle can be used to measure a right angle on even large objects. 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.

Related to standard AR.Math.Content.3.MD.C.7., this is a multisection lesson for the 3rd grade unit of study on area in relation to multiplication, complete with teacher notes.This lesson is designed to be taught with an 'I Do, We Do, You Do' format. Starting with an introduction slideshow, students will connect multiplication with previous concepts and skills such as repeated addition, skip counting, and equal groups. Then they will see a video and example problems which can be completed together as a class. Allow time for students to read and complete some of these example problems with a partner which will give time for questioning, addressing misunderstandings, and informal interventions. End the lesson with a preview of the next day's independent activity and an exit ticket using a quick image. 

An interactive applet and associated web page that demonstrate the properties of a 45-45-90 isosceles right triangle. The applet shows a right triangle that can be resized by dragging any vertex. As it is dragged, the remaining vertices change so that the triangle's angles remain 45 degrees, 45 degrees and 90 degrees The text on the page points out that the sides of a 45-45-90 triangle are always in the ratio of 1 : 2 : root 2 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 resource will enable students to determine flawed reasoning in a fraction comparison with unlike numerators and denominators.

This resource includes a flawed reasoning task that reflects 5.NF.5. Students must find the flaw in an argument and present it correctly. Then, they should provide a reasoning behind their thinking.

This OER explores the basic organization of the Pythagorean Solids. It contains both an activity as well as resources for further exploration. It is a product of the OU Academy of the Lynx, developed in conjunction with the Galileo's World Exhibition at the University of Oklahoma.

This resource includes two multi-step tasks where students connect diagrams and equations in order to solve real world problems. This task includes skills learned in the common core standard 5.NF.2

An interactive applet and associated web page that shows that angle-angle-angle (AAA) is not enough to prove congruence. The applet shows two triangles, one of which can be dragged to resize it, showing that although they have the same angles they are not the same size and thus not congruent. The web page describes all this and has links to other related pages. 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 the AAA similarity test works. Two similar triangles are shown that can be resized by dragging. The other triangle adjusts to remain similar and the angle-angle-angle elements are highlighted to show how they are involved in this test of similarity. (all three interior angles congruent). The web page describes all this and has links to other related pages. 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 reference book project at http://www.mathopenref.com.

An interactive applet and associated web page that shows how triangles that have two angles and a non-included side the same must be congruent. The applet shows two triangles, one of which can be reshaped by dragging any vertex. The other changes to remain congruent to it and the two angles and non-included side are outlined in bold to show they are the same measure and are the elements being used to prove congruence. The web page describes all this and has links to other related pages. 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.