From the American Mathematical Society, this database offers over 2 million reviews, abstracts, articles (some fulltext), books, chapters, and theses/dissertations from mathematical sciences literature from 1864 to the present.
From Cornell University, arXiv offers Open-Source Scholarly Articles in multiple formats covering mathematics, computer science, nonlinear sciences, quantitative biology, and statistics. All fulltext from 1991 to the present.
An index to over 40 Mathematics and Statistical journals covering theoretical and applied mathematics and statistics. It contains citations from 1935 to the present including some fulltext.
Sponsored by Wolfram Research Inc., MathWorld is an online mathematics reference tool covering a wide range of topics including algebra, geometry, calculus, and number theory.
The PBS lesson plans have everything you might want in a lesson plan, such as standards alignment, extension ideas, assessment, and much more. Plus, the plans incorporate video clips.
These outstanding science lesson plans for grades 3-12 go beyond the basic description to include interdisciplinary connections, extension activities, discussion questions, and lengthy standards alignment.