HP 40gs Graphing Calculator Programming

Two levels of programming are possible on the HP38G:

1. Saving Aplets (Function, Statistics applications etc.) where the user saves their equations or data entries, setups, notes and sketches under an Aplet name of their choice
2. Programming in the Program facility of the calculator.

The first method is viable and potentially useful for all calculator users especially students while the second relies on an understanding of computer programming and can be time consuming and frustrating to the non-expert.

An alternative is to use programs available on the Internet. All these options are considered here.

Warning: Programs, including saved Aplets use up memory which might better left available for calculation.

Writing and Saving Aplets

Example for Applicable Mathematics:
Upper tail normal probability, P(z > than a given value), is obtained with the function:

UTNP(mean, variance, standardised value)

This, among other functions, might be useful to store in the calculator in a Solve Aplet saved as TEESOLVE. Use the following procedure.

1. Highlight the Solve Aplet in Aplet and RESET (screen key) it.

2. Enter the equation in SYMB using Capital letters that relate to the variables. The function UTNP is accessed through:
   MATH
   P
   Move the cursor onto Prob then across and down to UTNP.
   OK
3. Save the equation:
   LIB
   Save (screen key)
   Type in TEESOLVE and OK
4. TEESOLVE now appears in the list of Aplets in LIB and other equations can be added to it (as well as notes or sketches but remember these use memory). Save any additions as before (don't rename the Aplet - just select OK).
5. In NUM, using the equation for UTNP, the solution for unknown mean, variance, z, or probability can be obtained if given three of the four values.