Delta Math — Online program which allows classwork, homework, and quizzes to be completed and graded online in real-time 

IXL — IXL provides comprehensive, standards-aligned math and language arts practice for K–12

JMAP — Resource for regents prep, extensive curriculum materials, and unit topics

Khan Academy — Confused about a specific topic? Perhaps you want to go beyond what you did understand. Khan Academy is a great resource for either, it is a compilation of videos and resources of actual unit topic lessons

Purple Math — Helping students gain understanding and self-confidence in algebra. Support for confusions and misconceptions

REGENTS Practice — Interactive Algebra regents practice questions where you can check your answers immediately. A printable version is also available

Math Open Reference — A free interactive math textbook on the web. Using interactive tools and compelling animations, Math Open Reference provides an engaging way to learn and explore Mathematics & Geometry.

Math Is Fun — Another free interactive math textbook on the web. 

Math Bits Notebook — Online study Mathematical resources for high school students.

Bright Storm — Video recorded lessons of effective teachers going through and explaining content.