Education Technology

Equation Operating System (EOS™)

The TI-84 Evo uses an order of operations system called Equation Operating System (EOS™).

The TI-84 Evo uses the following order of operations:

Parenthesis and Grouping Symbols

Exponentiation and Roots

Negation

Multiplication, Division and Fractions

Addition and Subtraction

EOS™ evaluates the functions in an expression in this order:

Order

Operation

1st

Expression inside parentheses

2nd

Functions that need a ")" and precede the argument, such as sin, log, R<>P menu items, ...

Note:This is to indicate "real" functions rather than commands.

3rd

Postfix operators

2 (SQUARE)

! (FACTORIAL)

T (TRANSPOSE)

-1 (INVERSE)

° (DEGREE)

r (RADIAN)

g (GRAD)

4th

Exponentiation ( ^ ) and roots ( x√ )

In Classic Mode, exponentiation using the (^) key is evaluated from left to right. The expression 2^3^2 is evaluated as (2^3)^2, with the result of 64.

In MathPrint™ mode, exponentiation using the (^) key is evaluated as 2^(3^2), with the result of 512.

5th

Negation "−"

Note: Unary prefix operators (currently only (-)) are special: In an expression like "A ^ (-)B" the negation must take precedence over exponentiation, while in an expression like "(-)A ^ B" negation has lower priority than exponentiation. This is how both CE and Evo work.

6th

Permutations "nPr" and combinations "nCr"

7th

Multiplication, implied multiplication, division, fractions

8th

Addition and subtraction

9th

=, <, >, ...

10th

and

11th

or, xor

12th

End of the line operators:

>f<>d

>DMS and new angle display conversions

>POLAR

>RECT

>n/d<>Un/d

Unit conversions in the Science Tools App ONLY

13th

z

14th

=and":"completes all operations and closes all open parentheses