http://www.mathaware.org/

The American Mathematical Society, the American Statistical Association, the Mathematical Association of America, and the Society for Industrial and Applied Mathematics announce that the theme for Mathematics Awareness Month, April 2010, is Mathematics and Sports.

• view and submit activities related to the theme
• see theme essays and this year's posters
• find out more about Mathematics Awareness Month

https://teknoclips.org/

The federally funded Capturing Teacher Knowledge (TeKno) project at the University of Arizona invites teachers to participate in a study designed to analyze how teachers think about ratio and proportions.

Participants are asked to:

• Fill out a background information online survey
• Take an online mathematics survey on ratio and proportion
• View and comment on 12 clips from math classrooms on ratio and proportion topics
• (Optional) Administer a student assessment on ratio and proportions twice, once as a pre-test and again as a post-test, before and after you teach ratio and proportions (instructions and copies are online)

For those teachers completing the task, the TeKno project will provide a $75 Amazon.com gift certificate. Participants collecting pre- and post-test data will receive an additional $50 gift certificate.

If you are interested, register at the site above, using this activation key: 640266615.

http://whyslopes.com/complex.html

Since we last featured the fractions section of Alan Selby's site "Appetizers and Lessons for Mathematics and Reason" in January this year, he has revised and expanded the section on complex numbers, organizing it under these topics:

• Addition and Multiplication [of vectors]
• What Are Complex Numbers?
• Addition and Multiplication Properties
• Second Way to Compute Products
• Consequences of Two Ways to Compute Products

These pages provide a way to introduce complex numbers before the study of periodic (unit-circle based) trigonometric functions.

For all of Selby's pages on high school mathematics and calculus topics, see:

http://whyslopes.com/