Casio fx115ES Plus

09082014, 02:00 PM
(This post was last modified: 09082014 02:28 PM by Don Shepherd.)
Post: #1




Casio fx115ES Plus
For a calculator that costs less than $20, this unit has some very interesting features, including:
The repeating decimals feature is particularly interesting. I entered a calculation that resulted in the fraction 385/1608. I pressed the key to get the decimal equivalent and it showed 0.239427860696517412935323383084577114 with a vinculum bar above the digits starting at 427. Amazing. 

09082014, 03:13 PM
Post: #2




RE: Casio fx115ES Plus
It is rather amazing what you get for $20. Sharp also has a model with similar capabilities, the ELW516.
There is a good comparison between the SHARP ELW516 and the CASIO fx115ES calculators at: http://members.bex.net/jtcullen515/Math8.htm More than a simple comparison, the two volumes presented here (175 pages) are also a good tutorial on how to use these models. The information is usable for newer Casio and Sharp scientific calculator models as well. 

09092014, 04:34 AM
Post: #3




RE: Casio fx115ES Plus
It also does numerical integration, BIN OCTAL HEX arithmetic, and the Plus added an integer function so you can calculate the remainder, though a MOD function would have been better. Still, I agree it's quite impressive for less than $20.


09092014, 10:42 PM
(This post was last modified: 09092014 10:43 PM by SlideRule.)
Post: #4




RE: Casio fx115ES Plus
I purchased mine for under $12 at __art (blanked on purpose). I use it as my calculator of first choice for my Technical Mathematics classes. I'm a longtime HP fan, going ALL the way back to the 65 BUT this Casio outperforms my prior choice calculator, the HP300s+. Like the WP31S I recently purchased, I don't need programming with the level of SOLVE and the depth of FUNCTIONS provided on the 115ES+.
BEST! SlideRule 

09112014, 11:54 PM
(This post was last modified: 09122014 03:05 AM by Joe Horn.)
Post: #5




RE: Casio fx115ES Plus
(09092014 10:42 PM)SlideRule Wrote: I purchased mine for under $12 at __art (blanked on purpose). Today I bought one there also, for $12.97, no shipping charges because they are nearby. The "recurring decimal" functionality is sweet; I've never seen it on a calculator before. EDIT: corrected "fraction" to "decimal". <0ɸ0> Joe 

09122014, 12:51 AM
Post: #6




RE: Casio fx115ES Plus
Here is a Youtube video featuring this calculator, and the presenter shows several ways to use this calc with students so that they can discover the rules for certain math concepts on their own instead of just hearing the teacher say "this is the rule." Toward the end of the video he also shows how to use the Preanswer and Answer functions to easily generate the Fibonacci sequence. Very cool.


09122014, 03:31 AM
(This post was last modified: 09122014 03:50 AM by Gerson W. Barbosa.)
Post: #7




RE: Casio fx115ES Plus  
09122014, 08:41 AM
Post: #8




RE: Casio fx115ES Plus
(09122014 03:31 AM)Gerson W. Barbosa Wrote: 1 ENTER + (04182014 05:24 PM)Thomas Klemm Wrote: I like to hit a key repeatedly and look what happens: With the HP48 you can use: Code: \<< SWAP OVER + \>> 0 1 LUCAS LUCAS LUCAS ... Code: \<< OVER SWAP * \>> [[1 1]1 0] [1 0] FIBO FIBO FIBO ... Cheers Thomas 

09122014, 08:54 AM
Post: #9




RE: Casio fx115ES Plus
(09122014 03:31 AM)Gerson W. Barbosa Wrote:About the same:(09122014 12:51 AM)Don Shepherd Wrote: Toward the end of the video he also shows how to use the Preanswer and Answer functions to easily generate the Fibonacci sequence. Very cool. 1 = = preanswer + answer = ... but on a nonprogrammable $13 calculator! 

09122014, 02:11 PM
Post: #10




RE: Casio fx115ES Plus
(09122014 08:41 AM)Thomas Klemm Wrote:(09122014 03:31 AM)Gerson W. Barbosa Wrote: 1 ENTER + On the WP 34S: Code:
or Code:
Cheers, Gerson. 

09122014, 02:14 PM
(This post was last modified: 09122014 02:14 PM by Gerson W. Barbosa.)
Post: #11




RE: Casio fx115ES Plus
(09122014 08:54 AM)Don Shepherd Wrote:(09122014 03:31 AM)Gerson W. Barbosa Wrote: Easier than 1 ENTER + g LSTx x<>y + g LSTx x<>y +... ?About the same: Nice! The only thing I dislike is prime factors being limited to 3 digits. 

09122014, 03:24 PM
Post: #12




RE: Casio fx115ES Plus
Quote:Nice! The only thing I dislike is prime factors being limited to 3 digits. Yeah, I'm not a big fan of that either, but this is a nonCAS $13 system after all. I think the repeating decimals function is the major feature of this guy. The Youtube video I mentioned in one post is very good, I am considering whether to use this calc with the students in my algebra class. I have not used any calculators in the last few years in my classes, but I very much like the idea of "let the students experiment and figure out the rule without me saying what the rule is". 

09132014, 03:10 AM
Post: #13




RE: Casio fx115ES Plus
(09122014 08:54 AM)Don Shepherd Wrote:(09122014 03:31 AM)Gerson W. Barbosa Wrote: Easier than 1 ENTER + g LSTx x<>y + g LSTx x<>y +... ?About the same: Various methods for various machines have been posted in this thread, but the Casio wins the "keystroke efficiency" competition (at least after a few iterations). As Don shows above, the Fibonacci Sequence has a 7 keystroke setup (including one shift key), and each iteration takes only 1 keystroke. Other sequences are similar: Pell Sequence: Setup: 0, =, 1, =, 2, Ans, +, ALPHA, PreAns (9 keystrokes) Iterate: = (1 keystroke) > 2, 5, 12, 29, 70, 169, ... (up to the 32nd Pell number, after which it flips into scientific notation and loses digits). Also, Casio has long supported multiple statements in one line (separated by a colon), which lets you execute an entire sequence of commands repeatedly, by simply by pressing the = key repeatedly. Very cool. Do any nonCasio algebraic calculators do this? <0ɸ0> Joe 

09132014, 10:06 AM
Post: #14




RE: Casio fx115ES Plus
(09132014 03:10 AM)Joe Horn Wrote: Also, Casio has long supported multiple statements in one line (separated by a colon), which lets you execute an entire sequence of commands repeatedly, by simply by pressing the = key repeatedly.Does this mean that the following can be used to calculate \(\pi\)? 0 = 2 = √ PreAns + 2 : 2 PreAns / Ans = = ... As I didn't consult the manual some parentheses might be missing. Quote:Very cool.Yes, indeed. Cheers Thomas 

09132014, 11:11 AM
(This post was last modified: 09132014 12:22 PM by Don Shepherd.)
Post: #15




RE: Casio fx115ES Plus
Quote:Does this mean that the following can be used to calculate \(\pi\)? Yes, Thomas, that yields 3.141592654 after 33 iterations. 

09132014, 01:51 PM
Post: #16




RE: Casio fx115ES Plus
(09132014 11:11 AM)Don Shepherd Wrote:Quote:Does this mean that the following can be used to calculate \(\pi\)? Very cool! And Thomas's having got it right without either calculator or manual was just übercool! 

09132014, 04:32 PM
Post: #17




RE: Casio fx115ES Plus
TI57:
CLR 1 x<>t 0 x<>t + x<>t + x<>t + ... 

09142014, 01:45 PM
Post: #18




RE: Casio fx115ES Plus
(09132014 11:11 AM)Don Shepherd Wrote: Yes, Thomas, that yields 3.141592654 after 33 iterations. Don, thanks for taking the time to confirm this. What bothers me a little is that it needs 33 iterations since that's what I get when the result is rounded to 10 significant digits: Code: PreAns Ans Where does it start to deviate? Cheers Thomas 

09142014, 05:39 PM
(This post was last modified: 09142014 05:48 PM by Don Shepherd.)
Post: #19




RE: Casio fx115ES Plus
Quote:Where does it start to deviate? My mistake, I was counting each press of the = key as an iteration and counting the keypresses until it showed 3.141592654. Each = key press executes expressions between colons. So it is actually 16 I think. I get exactly what you get. 

09142014, 07:57 PM
Post: #20




RE: Casio fx115ES Plus  
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