This page contains activities and resources that are appropriate for teachers at the 9-12 grade level for use as they reflect on, plan for, and implement Standards-based mathematics education in their classrooms. Click on the following links (or scroll down the page) to find the Table of Contents for each section.

i-Math Investigations are ready-to-use, online, interactive, multimedia math lessons. Complete i-Maths include student investigations, teacher notes, answers, and related professional development activities. Not every i-Math is currently complete, but they are all ready to be used.

Student i-Maths: For each i-Math Investigation, there is a specially-formatted student version that is classroom-ready. Student versions contain no irrelevant links and all teacher notes, answers, and professional development activities have been removed. All student i-Maths are listed on the Student i-Math page. This is the only page that needs to be bookmarked for classroom use.

	Investigating Linear Relationships: The Regression Line and Correlation Interactive computer-based tools allow students the opportunity to manipulate numbers easily and investigate the relationships between data points and sets. This i-Math Investigation uses an interactive linear regression tool to help students develop a conceptual understanding of the least-squares regression line and correlation.
	Using Algebra and Discrete Mathematics to Investigate Population Changes in a Trout Pond This investigation illustrates the use of iteration, recursion, and algebra to model and analyze a changing fish population. Graphs, equations, tables, and technological tools are used to investigate the effect of varying parameters on the long-term population. Preliminary Version - Applets run only on Internet Explorer or Netscape 4.7.4 for PC. Does not run on Netscape for Macintosh.
	Shedding Light on the Subject: Function Models of Light Decay In this investigation students develop and analyze exponential models for the behavior of light passing through water. Accompanying video clips show the i-Math in action in real classrooms. Preliminary Version - Applets run only on Internet Explorer or Netscape 4.7.4 for PC. Does not run on Netscape for Macintosh.
	Whelk-Come to Mathematics: Using Rational Functions to Investigate the Behavior of Northwestern Crows In this investigation students use rational functions to explore the possible reasons behind the observation that northwestern crows consistently drop a type of mollusk called a whelk from a height of 5 meters. Preliminary Version - Applets run only on Internet Explorer or Netscape 4.7.4 for PC. Does not run on Netscape for Macintosh.

Reflections on Teaching are activities designed to encourage thinking and discussion about teaching and learning mathematics. Most of these Reflection activities are centered around video vignettes of teachers teaching math or students learning math.

Facilitating Communication about Measurement, Exponents, and Scientific Notation Students need opportunities to communicate through reading, writing, listening, and speaking in mathematics classrooms. Multiple methods of communication can be used to help students reflect on their own ideas and the ideas of others. The video clips included in this example illustrate different methods and purposes of communication.

In this section you will find links to exemplary mathematics education resources on the internet. These Selected Web Resources can be used to improve the teaching and learning of mathematics for all students. They can help you understand and apply the NCTM Principles and Standards for School Mathematics. Each of these web resources has been carefully reviewed and approved by a panel of experts. This collection will grow and be modified based on review by the NCTM Illuminations Advisory Panel.

See the Selection Criteria and a list of the review panel members. You can nominate a site using this Application Form.

Click on a link below to see a summary page which briefly summarizes the content and purpose of the site. Click again to go to the site. Close the window of the external site and you're back at Illuminations.

	Math Forum (All topics / All grades): The Math Forum has information, challenges, and activities in mathematics across all grade levels. Contains resources for all grades, including grades 9-12.
	Eisenhower National Clearinghouse For Mathematics and Science Education (All topics / All grades): This site gives teachers a plethora of educational information, resources, and activities across all grade levels. Contains resources for all grades, including grades 9-12.
	The Guide to Math and Science Reform (All topics / All grades): One-stop directory for organizations, projects, and resources in the field of math reform. Contains resources for all grades, including grades 9-12.
	Mathnotes English to Spanish Math Glossary (All topics / All grades): An invaluable resource for bilingual math students. Contains resources for all grades, including grades 9-12.
	BBC Education Web Guide, Math (All topics / All grades): A superior collection of well-annotated links. Contains resources for all grades, including grades 9-12.
	The MacTutor History of Mathematics Archive (All topics / All grades): The MacTutor History of Mathematics Archive will help students appreciate the human side of math by becoming acquainted with the actual men and women who have created it over the centuries. Contains resources for all grades, including grades 9-12.
	Interactive Mathematics Miscellany and Puzzles (All topics / All grades): Alex Bogomolny's Interactive Mathematics Miscellany and Puzzles (also called Cut the Knot, in honor of another noteworthy Alexander) is an irresistible collection of puzzles, problems, and paradoxes. Contains resources for all grades, including grades 9-12.
	New York Times Mathematics Lessons (All topics / Grades 6-12): These well–constructed lessons let students see for themselves how math skills can improve their understanding of current events. Contains resources for grades 6 -12.

The internet is a vast storehouse of information and resources. Effective mathematics lessons can be created by tapping into the internet. For example, internet links can provide real-world data that can be analyzed or used to develop mathematical concepts. Other links may provide detailed information about areas in which mathematics is applied. Some websites provide tools that can be used to graph, visualize, or compute. The lessons plans in this section of the Illuminations site are examples of how internet links can be used to create effective Standards-based mathematics lessons.

Whelk-Come to Mathematics: Using Rational Functions to Investigate the behavior of Northwestern Crows - an i-Math lesson plan. In this lesson students use rational functions to explore the possible reasons behind the observation that northwestern crows consistently drop a type of mollusk called a whelk from a height of 5 meters. To view and use this lesson plan, click here and directly to the i-Math Investigation upon which it is based.

Clicking on the main link below will take you to Chapter 7: Grades 9-12 in Principles and Standards for School Mathematics (PSSM). Using this link will open another browser window in which you can navigate through the PSSM. To return to the Illuminations site, simply close the browser window that you are using to view the PSSM. Clicking on the other links will take you to specific standards for this grade band.

Standards for Grades 9-12
Number and Operations	Problem Solving
Algebra	Reasoning and Proof
Geometry	Communication
Measurement	Connections
Data Analysis and Probability	Representations