Basic Use of the TI-84 Plus

Topics: Key Board Sections

Key Functions

Screen Contrast

Numerical Calculations

Order of Operations

Built-In Templates

MATH menu

Scientific Notation

The – key VS the (-) Key

Lower Center (White Keys): Numeric Keys, L1-L6, Catalog, ANS, and the (-) key

2nd Key (Blue) and Alpha Key (green): Accesses symbols and functions written in the corresponding color

The “ON” button; also the “OFF” button when used with the 2nd key

Navigation Pad: moves curser on the display and changes the image contrast when used with the 2nd key

Lower Right (Gray Keys): Basic Operations such as addition, subtraction, multiplication, and division, as well as the “ENTER” and “SOLVE” key.

Lower Left (Black Keys): Basic Functions such as the square, square root, and log functions

MODE: Allows you to change the way the TI-84 interprets and displays information

Top Row (Gray Keys): Most of these are used for the graphing functions. These functions will be discussed at greater length in a future workshop.

Middle Section (Black Keys): Special Program Keys such as Trigonometry functions, grouping symbols, and access to built in applications and templates.

Clearing the Memory

When borrowing a calculator from the SRC, you may want to clear any definitions, programs, lists, or functions that the others have set.

To Clear:

• Press 2nd and MEM (the plus symbol)

• Select option 7: Reset

• Select option 1: All RAM…

• Select option 2: Reset

Basic Calculations

For most arithmetic you will type in the expression and press “ENTER” to obtain the solution.

Try: 239 − 186 52 × 33 374 ÷ 17 23 + 51 + 18

Order of Operations

The calculator follows the order of operations:

The calculations within Parentheses and other grouping symbols are done first.

Exponents are resolved next.

Multiplication and Division are then done moving from left to right.

Addition and Subtraction are last, also going from left to right.

Examples

36 − 12 ÷ 2 The division is done before the subtraction.

6 × 5 + 16 ÷ (7 − 3) First the subtraction inside the parenthesis is done, then the multiplication and division, and lastly the remaining addition is completed.

32 − 7 ÷ 6 The squaring of 3 is done first, then the division, then the subtraction.

Note that the solution is given as a decimal. The number of decimal places displayed can be changed by pressing the MODE button. Press MODE, and change the “Float” to 3. To exit, press 2nd, then MODE to “QUIT” or use “CLEAR”. Now try the problem again. See the difference?

Recall: The division bar IS a grouping symbol.

Consider: 2∗6

5−2=

12

3= 4

What is the result if you enter 2 × 6 ÷ 5 − 2?

Why is the result different?

To address this issue you can use parenthesis or a template found by using ALPHA and F1 (the “y=“ key).

Templates in the F1 Menus To locate these menus, press ALPHA then a top row key

FRAC (y=): fractions, mixed numbers, complex or “stacked” fractions, conversions between fractions and decimals

FUNC (window): absolute value, summation, derivative at a point, definite integrals, log function

MTRX (zoom): matrix template up to 6x6

YVAR (trace): Captures equations from the Y= list

When you press the MATH key, 4 menus become available, each with several options to choose.

MATH

NUM

CPX

PRB

The MATH Menu Options 1-5

1: Frac : This will change your decimal into a proper or improper fraction.

2: Dec : This will change your fraction into a decimal.

3: 3 : This is like the 𝑥2 function key for cubes.

4: 3√ ( : This is the template for a cube root

5: x√ : Allows for roots greater than 3

Try the following:

1) a) Write the decimal approximation 9656

3692 to three

decimal places.

b) What is the exact answer as a reduced fraction?

c) What is the solution as a mixed number?

2) a) What is the cube root of 5 written to 6 decimal places?

b)What happens when you have the TI-84 convert this decimal to a fraction?

c) Why do you think this happened?

Shortcuts These keys, along with the direction pad, can make corrections without

having to re-type the whole line.

Delete (DEL): This eliminates the symbol directly beneath the curser box.

Insert (INS): Found by using 2nd and DEL, this allows you to insert new symbols in front of the chosen character.

CLEAR: Pressing this will delete the current line of text.

ANS: This will enter the value given as the answer to the previous question even if you cleared it from the screen.

ENTER: Use the curser to highlight a previous line then press ENTER to copy it to the current line.

Understanding Scientific Notation For solutions that are very large or very small numbers, the TI-84 will use scientific notation (s.n.).

Recall: In s. n. only 1 digit is written to the left of the decimal point and the solution is multiplied by a power of 10.

Ex: The population of the US is approx. 320,196,500 people or 3.202 × 108 in scientific notation.

On the TI-84 this will appear as 3.202E8

Hence, the “E” replaces the “× 10“ and the power is written as number instead of an exponent.

− versus (−)

The − key (gray button) represents the operation of subtraction.

The − key (white button) represents the opposite or negative value of what follows.

Using them interchangeably will result in an error message.

Example: Subtract negative 8 from 36

Watch for future technology workshops that will explore the graphing, statistical, and modern algebra capabilities of the TI-84.

Additional Resources

• http://education.ti.com/en/us/products/calculators/graphing-calculators/ti-84-plus/features/features-summary

• http://hotmath.com/graphing_calculators/

• http://mtl.math.uiuc.edu/non-credit/basic84plus/

• http://www.prenhall.com/divisions/esm/app/graphing/ti83/