SMath Studio - Tiny, powerful, free mathematical program with WYSIWYG editor and complete units of measurements support.
Mathway - Mathway is a freemium math solving app that helps you find the solutions to any math problem you can imagine.
Wolfram Mathematica - Mathematica has characterized the cutting edge in specialized processing—and gave the chief calculation environment to a large number of pioneers, instructors, understudies, and others around the globe.
Math.com - Math.
MATLAB - A high-level language and interactive environment for numerical computation, visualization, and programming
Delta: Math helper - With Delta: Math helper, quickly solve any math problem with an algorithm. Save time checking your homework or studying for a test, it’s free!