On the 89 it would draw the actual fractions and show exponents in superscript rather than only using parenthesis. You could also scroll up to previous entries and bring them back to the editor (or get previous answers).
The mistakes you avoid from not having to count parenthesis and being able to easily access previously typed equations was really helpful.
The hard part was by far typing complicated expressions into the stupid TI-83, navigating its terrible menu system, getting it to output what it was supposed to, and figuring out what was printed on the screen.
Coming up with the expressions to type took only a tiny fraction of the time of actually punching it in.
What a tremendous waste of students’ time and attention. Might just as well test emoji typing speed.
The SAT math is so rudimentary that it's difficult to use a calculator beyond its basic arithmetic functionality (unless it's been changed since I took it). I bet most people would get similar scores with and without calculators.
In college, calculators were never allowed in exams. They just constructed each exam problem so that you didn't need to perform arithmetic with large numbers. It does make it seem like exams were written to sell calculators...