Microsoft Mathematics 4.0 is a free download from Microsoft. Mathematics 4.0 is a set of math tools for students to use. It helps students learn how to solve equations step by step along with learning the fundemental concepts in pre-algebra, algebra, trigonometry, physics, chemistry and calculus.

It includes a graphing calculator that works just like a handheld calculator. There are also tools for evaluating triangles, converting units, and solving systems of equations.

The layout is similar to the popular handheld graphing calculators. It is easy to use and navigate, and free.

This is a great resource for math and science teachers and students.

READ MORE - Microsoft Mathematics - math help and graphing calc

The Khan Academy is a not-for-profit with the mission of providing a world-class education to anyone, anywhere.

They have tons of videos (over 1800) with lectures on reviews of different topics, including math, science, humanities, test prep and more. The videos are very well done and I share them with my students as a great review or supplemental resource for them.

The site can also just be browsed as each video is listed on the main page. Below you can see a section of the main page, which starts with the search bar and then Algebra. 

READ MORE - Khan Academy - free video lectures on math, science and more.