The required calculator is the TI-30XIIS. The Mathematics departmental policy states that no other calculator is allowed for any Math 123 tests/exams or quizzes, including the final exam. You must have a physical TI-30XIIS model, not a virtual calculator. You may not share calculators during quizzes or tests/exams. This TI-30XIIS Resources page includes videos about using the TI-30XIIS.
A physical TI-30XIIS is the only calculator that may be used on exams. However, some assignments may require the use of more powerful online calculators. You are encouraged to use free online calculators and programs for these assignments. This Online Calculator Resources page includes links and videos for each online calculator.
The Comparison: Online Calculator Resources vs. TI-30XIIS document distinguishes which skills should be completed using each resource (and provides information about the types of questions you could be asked on exams).
When you're typing the formulas into the TI-30XIIS, it can be helpful to do it a piece at a time (working from the inside out) and then use the answer button to keep going. You may find this TI-30XIIS Resources page, which includes videos, helpful.
For example, I might type the following into my calculator to solve Example 1 in the Lesson 2 notes.
1+.029/12 ENTER
ANS ^ (12 * 6) ENTER
ANS -1 ENTER
ANS / (.029/12) ENTER
ANS * 500
Be sure to use the answer button so that you don't round in intermediate steps.