gratis - Free alternative to step-by-step-solution feature of Wolfram|Alpha Pro? - Software Recommendations Stack Exchange
Wolfram|Alpha Pro
Wolfram|Alpha Pro Teaches Step-by-Step Arithmetic for All Grade Levels | by Tech-Based Teaching Editor | Tech-Based Teaching: Computational Thinking in the Classroom | Medium
Wolfram Alpha Pro runs rings around today's search engines - GCN
Resources for Students | Center for Assistance with Statistics and Mathematics | University of Wyoming