For those of us that used those calculators in engineering class, the math that is displayed by the calculator also looks like what's in the textbook, making it easy to check if one has entered the right thing in the calculator.

Here's a simple example from their documentation: https://education.ti.com/en/customer-support/knowledge-base/...

Using the Python repl doesn't display nice math as far as I know (let me know if there's a way to make it so it), as you'd have in an environment for doing symbolic math (eg. https://www.wolframalpha.com/input?i=integrate+sin+x+dx+from... )

Another thing if I remember correctly one could do is something like 3_ft*3_ft>_m^2 to convert 9 square feet in square meters, and do things like keep units throughout a calculation as a quick check that the calculator input is sane.

Take a look at Sage (for PCs) and khikas (for calculators).