Settings that should never change. MATHPRINT, so entries look like your textbook. NORMAL and FLOAT, for full precision. A FIX digit silently rounds every answer and costs accuracy marks. Near the bottom, STATWIZARDS: ON (statistics commands open a fill-in form) is the factory setting. Re-check it on a borrowed or reset calculator. STATDIAGNOSTICS: ON (regressions report ​r​ and ​r2​) is not a factory setting: it ships OFF, so turn it on yourself and check it every time you use an unfamiliar calculator.

The one that changes: RADIAN vs DEGREE. Use DEGREE when the problem measures angles in degrees, and RADIAN for radian measure and any calculus that involves trig. Maths AI SL uses degrees only: set DEGREE once and never touch this row again. The status bar along the top of every screen shows the current choice; make glancing at it a reflex.