KhanAcademy

Khan Academy is a non-profit education site that specializes in various topics, including math, physics and chemistry. It has a lot of quality content and is the perfect site for a Liceo student who wants to learn more or has a doubt in some topics. Khan Academy also offers test preparation (PSAT, SAT, GMAT).

Wolfram Alpha

Our number one choice when you need help in math, it offers explanations and calculates almost everything you input. Though it comes at a price, but the lite version is just fine.

Codecademy

Do you like code? This is the perfect website for you to learn. It teaches you various programing languages including: python, c++, html, css, java script, etc. Remember code is the future.

Mathway

Mathway is an online math solver that includes a very powerful and good looking interface.

Symbolab

Another alternative for math and science that is completely free and solves almost every kind of equation.