TI-84 Calculator Reference Sheet: Buttons & Symbols

A lot of TI-84 functions don’t have their own key — they’re one press away, tucked inside 2ND or the MATH menu, which is exactly why “where is ___ on a TI-84” is such a common search. This is a lookup for the ones people ask about most, grouped by what they do rather than where they physically sit.

Negative sign vs. subtraction

The TI-84 has two different minus signs, and mixing them up is the single most common syntax error on the keypad. (-) is the small key on the bottom row, right before ENTER — that’s the negative sign, and it belongs directly in front of a number: (-)5. The − on the right-hand operator column (with +, ×, ÷) is subtraction, and only goes between two values: 8 − 5. Typing 8 - -5 with the wrong key in the wrong spot is what throws a syntax error, not the math itself.

π and e

• π — 2ND + ^ (the caret key, top-right area). π is printed in yellow above it.
• e — 2ND + LN pastes e^(, the start of an exponential. There’s no key that inserts a bare e by itself; if you want the constant on its own, type e^(1) and evaluate it.

Percent

There’s no dedicated % operator anywhere on the TI-84 Plus family, CE included — this trips people up because plenty of other calculators have one. Do the conversion by hand instead: to take 20% of 150, type 150 × 20 ÷ 100 (or 150 × .20), not 150 × 20%.

The equal sign

= isn’t needed to evaluate an expression — you just type the expression and press ENTER. Where it actually shows up is comparisons: 2ND + MATH opens the TEST menu, and 1: = is the first entry (alongside ≠, <, >, ≤, ≥). This is what you reach for inside a program’s If statement, or any expression that needs to test whether two values are equal rather than compute a result.

Roots and powers

• x² — squares the entry, dedicated key.
• ^ — raises to any power.
• 2ND + x² — √(, square root.
• MATH → 4: ³√( — cube root, its own dedicated shortcut. See How to Do a Cube Root on a TI-84.
• MATH → 5: ˣ√ — general nth root, typed as n then ˣ√ then the value.

Trig, inverse trig, and the ones with no key at all

sin, cos, and tan are dedicated keys, evaluated in whatever angle mode is currently set. 2ND + sin/cos/tan gives the inverses (sin⁻¹, cos⁻¹, tan⁻¹) — that’s arcsin, arccos, and arctan.

Secant, cosecant, and cotangent have no key or menu entry at all — the TI-84 doesn’t implement them directly. Use the reciprocal identities instead: sec(x) = 1/cos(x), csc(x) = 1/sin(x), cot(x) = 1/tan(x). Typing 1/cos(30) works, or evaluate cos(30) first and hit the x⁻¹ key (top-left of the trig row) to invert the result you just got.

Degree symbol (overriding the angle mode)

If your mode is set to Radian but you need to plug in one angle in degrees, 2ND + APPS opens the ANGLE menu, and 1: ° pastes a degree symbol after your number — it forces that one value to be read as degrees no matter what mode you’re in, without making you switch modes and back.

Infinity

There’s no infinity symbol or key. For anything that conceptually needs one — evaluating a sum, or checking what a function approaches — the standard workaround is scientific notation: use a very large number like 1E99 in place of infinity, or push the TABLE feature’s independent variable out to a large value and watch where the output settles.

Factorial and absolute value

Both are one level deeper in the MATH menu: factorial is MATH → PRB → 4:! and absolute value is MATH → NUM → 1: abs(. Full writeups: How to Do Factorial on a TI-84 and How to Do Absolute Value on a TI-84.

Try it yourself

The TI-84 calculator on this site skips the menu-digging — type pi, e, sqrt(x), cbrt(x), or 2ND + sin/cos/tan directly as text instead of hunting through MATH submenus. The full typed syntax is in the docs.