I am listing the useful links for young students.
Wolfram|Alpha introduces a fundamentally new way to get knowledge and answers--
not by searching the web, but by doing dynamic computations based on a vast collection of built-in data, algorithms, and methods.
BioWiki
ChemWiki
Digital Library for Earth System Education (DLESE)
Euclid Solving math and geometry problems
GeoS End-to-End Geometry Problem Solver
Knowledge Door
MathWiki
MathChase
Math.com
Math.com is dedicated to providing revolutionary ways for students, parents, teachers, and everyone to learn math. Combining educationally sound principles with proprietary technology, Math.com offers a unique experience that quickly guides the user to the solutions they need and the products they want. These solutions include assessment, on-demand modular courses that target key math concepts, 24/7 live online tutoring, and expert answers to math questions.
Math Calculator offer a free scientific calculator. In addition we are constantly adding new calculators to our site. Here are our algebra, geometry, trigonometry, graphing, and calculus calculators. In addition to those category-based collections, in the section below we offer a collection of some of the best math-related calculators from around the web
NCERT Textbooks for Download
Open Educational resources
The worldwide OER movement is rooted in the human right to access high-quality education. The Open Education Movement is not just about cost savings and easy access to openly licensed content; it’s about participation and co-creation. Open Educational Resources (OER) offer opportunities for systemic change in teaching and learning content through engaging educators in new participatory processes and effective technologies for engaging with learning.
Open Textbooks
OpenStax
OpenStax is a nonprofit based at Rice University, and it’s our mission to improve student access to education. Our first openly licensed college textbook was published in 2012, and our library has since scaled to more than 25 books for college and AP courses used by hundreds of thousands of students. Our adaptive learning technology, designed to improve learning outcomes through personalized educational paths, is being piloted in college courses across the country. Through our partnerships with philanthropic foundations and our alliance with other educational resource companies, OpenStax is breaking down the most common barriers to learning and empowering students and instructors to succeed.
PhysWiki
Plays recently launched hundreds of free educational and fun online games which can quickly be played from the browser. We try to publish at least a couple additional games everyday at https://plays.org/math-games/
Pigly a free (and ad free) guide which helps teach kids about math and finance.
RefDesk
School Database
The Engineering Toolbox
US DAVIS CHEM WIKI
