Temperature conversion - tests

Once a program has been written, it is a good idea to try it out. You can run the program directly by keying [Prog] [1] (if your program was stored in the first program area). For the conversion between Farenheit and Celsius (or vice versa), you can try the following:-

A=1, B=212, then 100 (Celsius) is displayed
A=1, B=32, then 0 (Celsius) is displayed
A=1, B=86, then 30 (Celsius) is displayed

A=2, B=100, then 212 (Farenheit) is displayed
A=2, B=0, then 32 (Farenheit) is displayed
A=2, B=30, then 86 (Farenheit) is displayed

If you get Syntax ERROR, then there is a "bug" (an error) in your program. Using the <> cursor key, the calculator will return to edit mode and show a flashing cursor after the point where the error occurred. This will give you an indication of where things went wrong. It may be obvious what the problem is but sometimes it may require quite a bit of investigation of the logic of your program. In the case of the temperature conversion program it may be because it has been keyed in incorrectly. Note that this program should be 40 steps in length. If you have more or less than this then this may indicate that it hasn't been keyed in right.

Temperature Conversion - the program

The logic for the temperature conversion program was presented previously. Here is the logic converted into a program for the fx-50F:-

?→A:?→B:If A=1:Then (B-32)x(5÷9)▲Else Bx(9÷5)+32▲IfEnd

This is pretty much how the program looks when keyed into the calculator in edit mode. Special Program Commands (? → : If = Then ▲ Else IfEnd) are input using the [SHIFT] [P-CMD] keys. The cursor key (marked Replay) is used to switch between various screens of commands. Memory variables A and B are input using [ALPHA] and [A] or [B] keys. The ":" Separator Code command is used frequently and can be alternatively input using the [EXE] key.

Temperature conversion - the logic

So what do we want to do when we convert between temperature scales? Clearly we either want to convert between Farenheit and Celsius or vice versa, so it would be good to be able choose between these two options.

So in our program we need two inputs called A and B, say; A will record what type of temperature conversion we want (for example, use 1 to indicate Farenheit to Celsius conversion and 2 to indicate the reverse) and B will record the temperature (in Celsius or Farenheit).

The logic behind a program would be:-

Input A (1 indicates F to C, 2 indicates C to F)
Input B (the temperature)
If A = 1
   Display (B-32)x(5/9) (the temperature in Celsius)
Else
   Display Bx(9/5)+32 (the temperature in Farenheit)
If-End

Temperature conversion

The conversion between the Celsius and Farenheit temperature scales is an easy example to program on this calculator.

On the Farenheit temperature scale the freezing and boiling point of water are 32F and 212F, respectively. On the Celsius scale these points are 0C and 100C, respectively.

To convert from a temperature in Farenheit to one in Celsius, we subtract 32 from the temperature, multiply by 5 and divide by 9. So 212F is ((212-32)x5)/9=100 C, as expected.

To convert from a temperature in Celsius to one in Farenheit, we do the inverse of the above, namely we multiply the temperature by 9, divide by 5, and add 32. So 100C is ((100x9)/5)+32=212F, as expected.

Creating a program

Here's how to go about creating a program on this calculator. Follow this series of key strokes. Each key to be pressed is indicated by [..]; for example, [MODE] means press the Mode key. An explanation appears in the (..) brackets after each key press.

• [MODE] [6] (Program Mode entered)
• [1] (Edit program)
• [1] (Program 1 selected)
• [1] (Comp run mode selected)

This takes you to the point where you can begin keying in your program. One thing to note about the display at this point is that 000, i.e. zero, programming "steps" have been used so far. This number increases for each step in the program that you add. In all there are 680 steps you can use shared between four programs.

Note also that different run modes can be selected (Comp, Cmplx, Base, SD, Reg) but Comp is the most basic one.

Note also that only four programs can be input on this calculator (labelled 1 to 4). Just select whatever number is currently free if you wish to key in a new program.

To exit from a program press [AC] or [SHIFT] [EXIT]. This takes you back to the "Edit Program" display which has P - 1234 680. The 680 in this case indicates the number of program steps remaining.

To exit back to calculator mode press [MODE] [1].

Online manual

The manual for this calculator can be found at support.casio.com/pdf/004/fx-50F_PLUS_E.pdf.

This could be useful if you are on the move.

How it looks

One of the problems I was experiencing with another Casio calculator that I own (the fx-4500P) is that I have difficulty in seeing the keys properly. One of the reasons that I bought this fx-50F Plus is that I liked the clean layout and easy to read keys and key markings.

Why?

I am currently working my way through a couple of OU Maths courses and I bought this calculator recently to help me in my studies. As there doesn't seem to be any programs for this calculator on the internet, I decided that I would start this blog to detail some programs of my own and to add some notes about this calculator from time to time. Hopefully someone might find this useful.