II. Function Keys
I. Store
1. The ability to store values in different variables is a key feature on the TI83 and the TI84. By storing a value in a variable, you can then use that variable in expressions, programs, lists, matrices, etc. The value will remain the same on the home screen until you change it.
The simplest way to store a value in a variable is to use the and keys. If you do this you do not have to access the ALPHA mode.
Example: To store the value ln 1.5 in the variable X, calculate ln (1.5) then press .
One of the most useful ways to utilize the store feature is to check a solution to an equation you have solved.
Example: Suppose you have solved the equation and you want to check your solutions . You can check these very easily on your calculator.
Store the first
solution in X. 

Enter the
equation using X and see if it is 0. 

Repeat with the
other value. 
Storing a value in X will not affect a graph.
You can store a value in any variable if you use the key. For example, to store the value 15 in the variable N, you would press: 15 .
2. ENTRY is the name for a storage area in the TI83 and the TI84. To access ENTRY press . You can press these keys and recall numerous entries, up to a total of 128 bytes. Since there is a storage limit, the number of entries you can recall will vary.
Once you have recalled an entry you can then edit it or just reevaluate it.
3. ANS is a variable that has the value of the last answer. You can use it in an expression or with a function.
Example: Evaluate 5.6 * 12.7 and then divide 110 by the answer. Then take that result and multiply it by 50.
Evaluate 5.6
12.7 .


Enter 110 and press
. 

Press
50 .
