Conventions and language:
calculator buttons will be typeset like this,
menu titles will be typeset like this
,
menu items will be typeset like this,
and user-input will be typeset like this.
A string of consecutive actions/selections
will be delimited by arrows (→).
The stuff entered on the left side of the screen is called “input”
while the stuff displayed on the right side is called “output”.
Note that every menu item is preceded by a number or letter
that indicates a key-press that selects that item.
E.g. 6: ZStandard under the Zoom
menu
can be selected by pressing 6.
Effective Input Entry and Home Screen Navigation
The most recent output is stored to a special variable called Ans.
This Ans will pop up on the screen automatically
if the first key you press with an empty input is an operator (e.g. +),
but Ans can be accessed manually by pressing
2nd→(-).
Running the ENTRY command by pressing 2nd→ENTER will place the previously run input back onto the input line. Repeatedly running the ENTRY command will cycle through the history of the previously run inputs.
The arrow keys can be used to move around the input that is currently being entered. Pressing 2nd followed by a left- or right-arrow key will jump the cursor to the beginning or end of the input line. The DEL key will delete the thing under the cursor, called a token, while the CLEAR key will delete all tokens under and to the right of the cursor, unless the cursor is at the end of the line, in which case CLEAR will clear the entire input line. When editing a single input, the default behaviour is that pressing a key will replace the token currently under the cursor with the result of that key. To change this behavior to insert tokens to the left of the cursor instead, press 2nd →DEL to enter insert mode; while in insert mode the cursor will appear as an underscore instead of a block.
Storing Variables and Functions
Variables and functions can be stored in the calculator for easy access.
Suppose a computation involves the force of gravity on earth.
There’s no need to type 9.80665 more than once;
that constant can be stored using the → command
to any of the alphabetic variables
indicated to the top right of most keys on the calculator.
For example entering 9.80665 then pressing
STO→→ALPHA→TAN
will store 9.80665 to the variable G,
the letter located over the tangent key TAN.
This constant can now be used in computations
simply as G in the input line.
Similarly, entire functions can be stored in the calculator for easy use.
Pressing the Y= button towards the top left of the calculator
opens a screen where up to ten functions,
Y₁ through Y₀, can be entered.
The novel thing is that these functions can be accessed from the home screen too.
Suppose a computation requires us to evaluate the function \(f\)
defined by the formula \(f(x) = \sin\bigl(\cos(x)\bigr)\) at \(x=8.\)
Instead of typing the formula for \(f\) into the home screen twice,
simply enter that formula for Y₁,
and on the home screen press
VARS→Y-VARS
→Function…→Y₁,
to place Y₁ on the home screen,
then evaluate Y₁ at that input
using the usual function evaluation notation, Y₁(8).
The value of any variables
can be placed (recalled) onto the current input line
with the RCL command.
Press 2nd→STO→ followed by
any letter variable accessed by pressing ALPHA
or any other variable found under VARS to do so.
TI-BASIC Programming
TI-83/84+ calculator come equipped
with a programming language called
TI-BASIC.
To create a new TI-BASIC program, press PRGM,
navigate over to the NEW
menu,
and select Create New.
First name the program.
Having entered a name a Program Editor screen will display
where the program will be written.
That lonely colon : indicates
the beginning of a line of code.
If you exit the Program Editor screen
you can return to it by pressing PRGM,
navigating over to the EDIT
menu,
and selecting your program.
While inside the Program Editor,
pressing PRGM again
will display all the
control-flow keywords under CTL
and input/output keywords under I/O
needed to write a program.
For the details on programming in TI-BASIC consult a calculator’s guidebook or find a tutorial elsewhere online.
Bonus: TI-30XIIS
This calculator can store variables.
Given a number, pressing STO►
will bring up variables A, B,
C, D, or E,
into which can be stored that value.
Then pressing MEMVAR
will allow you to use that stored value.