Most online calculators reduce the user experience to returning results in response to some input data. As a tools developer, I know this quite well.
I’ve been asking to myself, “Why not use a different approach and build calculators that behave as oracles?” By an oracle I mean a black box that converts the input data into a user’s question (the query) and the output (the response) into the answer to the question.
To truly behave as an oracle, said tool should also take care of most of the tasks a user is expected to do. The tool should also “react” to mistakes made by a user.
With that in mind, here is my first attempt at turning an online calculator into an oracle-like tool: The Ideal Gas Law Oracle (http://www.minerazzi.com/tools/ideal-gas-law/oracle.php).
This one even takes care of significant figures and unit conversions. Chemistry teachers and students might find it useful. For instance, teachers can use the tool to add content to lecture notes, quizzes, and tests. Students can use it to double-check exercise results from homeworks and textbooks.