How to Do Absolute Value on a TI-84 Plus

Absolute value strips the sign off a number — it’s the distance from zero, which is always non-negative. |5| = 5 and |-5| = 5, but the calculator needs a specific syntax to know you mean that and not just parentheses.

The syntax

On a TI-84, absolute value is the abs( function, found under MATH → NUM → 1: abs(. Type abs(-7) and evaluate it, and you get 7. It works the same way on any expression, not just a single number: abs(3 - 10) evaluates the inside first (-7) and then strips the sign, giving 7.

A common mistake is typing -abs(7) when you meant abs(-7) — the first negates after taking the absolute value (giving -7), while the second takes the absolute value of an already-negative number (giving 7). The position of the minus sign relative to the parentheses changes the answer.

Worked example

For abs(2 - 9) + abs(4): the first term is abs(-7) = 7, the second is abs(4) = 4, so the total is 11.

Try it yourself

On the TI-84 Calculator, just type abs( directly into the expression line the same way you’d type sqrt( — for example, abs(-12.5) — and press Enter. It follows the same order of operations as the real calculator, so nesting it inside a larger expression works exactly as shown above.