Calculator lots of decimal places - Page 1
Forum section: electronics / general

author: Flump
author_rank: Frequent Contributor
timestamp: September 25, 2015, 04:50:44 pm
content: Can anyone suggest a cheap to purchase calculator that goes down to 14 decimal places ?my old casio m1 and new casio fx-85gt won't.

author: LabSpokane
author_rank: Super Contributor
timestamp: September 25, 2015, 05:24:20 pm
content: I have to ask: what are you working with that requires 14 digits of precision?

author: DenzilPenberthy
author_rank: Frequent Contributor
timestamp: September 25, 2015, 05:29:42 pm
content: Windows calculator?...but yeah, what are you doing that needs 14 significant figures?

author: LabSpokane
author_rank: Super Contributor
timestamp: September 25, 2015, 05:35:42 pm
content: I just checked NIST and I've yet to find a physical constant listed beyond 12 sig figs. I'm sure that there is one, but I'm not seeing it. My HP 35s has a fourteen digit display, but that's because it's programmable not because anyone would realistically use that many digits.

author: alsetalokin4017
author_rank: Super Contributor
timestamp: September 25, 2015, 05:40:16 pm
content: I was about to ask the same thing.The answer of a calculation cannot be more precise than the _least precise_ value that goes into the calculation. (See the topic "Significant Digits" in your favorite reference.) So if you are doing calculations with measured values, a need for 14 sig digs in the result means that you are able to measure all of your measured values to a precision of that many digits -- and that is pretty darn rare.False precision is a particular bugbear of mine. I often see people doing some calculation from measurements or constants, like 3.1415 (the constant pi) x 2.567 (a measurement from a micrometer or meter) = 8.0642305, which is false precision and is almost certainly _wrong_ since the right value could be 8.0642304, or 8.0642306, or many other values down in the last few digits of precision.That being said, my old Sharp EL-520W has ten digits of precision, and that's a lot.If you really _need_ 14 significant digits maybe a software calculator like SpeedCrunch is a better choice than a handheld standalone.

author: JacquesBBB
author_rank: Frequent Contributor
timestamp: September 25, 2015, 06:04:50 pm
content: Quote from: alsetalokin4017 on September 25, 2015, 05:40:16 pmThis is what you find in physics textbooks, but it is wrong in everyday research practice.Indeed, the final accuracy of a result will be limited by the less known contribution, but the reason often for requiring much more digits, is the ability to track errors in a computation.If you find that a program does not give the expected result, even at 10^-13, while owing to the round of error you expect a maximal error of 10^-15, then you know that there is a bug in the software, and yo can track it because of these small differences.If you truncate everything, you do not detect the bug, that can rise to much larger values for a different setting of the program. So the necessity for precise output is the ability of tracking errors, and verifying the consistency of the code.

author: alsetalokin4017
author_rank: Super Contributor
timestamp: September 25, 2015, 06:10:24 pm
content: Ok, fine, but if you cite a result with too many significant digits in a calculation involving _measurements_ on one of my exams, I'll still flag it and mark it wrong.

author: pelule
author_rank: Frequent Contributor
timestamp: September 25, 2015, 06:52:32 pm
content: I just checked. Windows calculator shows32 working digits in scientific mode. I guess, that's enought:Calculated: 12345678901234567890123456789012 - 1 = 12345678901234567890123456789011

author: LabSpokane
author_rank: Super Contributor
timestamp: September 25, 2015, 06:57:33 pm
content: Quote from: JacquesBBB on September 25, 2015, 06:04:50 pmOf course *intermediate* calculations retain full precision. The answer is ONLY correct when specified to the proper amount of significant figures and associated error. What a calculator or software program does internally and what it displays are two entirely different things.Scientific research and engineering play by the exact same rules when it come to significant figures, by the way.

author: jpb
author_rank: Super Contributor
timestamp: September 25, 2015, 07:11:45 pm
content: My desktop HP OfficeCalc 300 has 14 digits. It is not scientific though. Most programming languages and things like Mathematica or Maple will do any number of digits.As most people have said, a lot of digits are normally way over the top. It may be useful to avoid rounding errors if taking the difference between two large numbers but normally in those circumstances you probably want to express your problem differently anyway.

author: Flump
author_rank: Frequent Contributor
timestamp: September 25, 2015, 07:51:10 pm
content: thanks for the replies so far, i am studying for an exam and its a revision questionI will need to take the calculator into the exam too so cant use the windows one,no matter how hard i try i cannot get to grips with scientific notation

author: JacquesBBB
author_rank: Frequent Contributor
timestamp: September 25, 2015, 08:11:41 pm
content: Quote from: LabSpokane on September 25, 2015, 06:57:33 pmThis is wrong.In fact, all scientists do not proceed in the same way on this matter.Some will follow the textbook rules of not presenting more digits than the real accuracy of the data,but in the field that deal with the most accurate data and computations, very often the results are given with much moredigits than the real accuracy of the data.This is to allow others to be able to recover the results, and to follow one version from another.

author: Andy Watson
author_rank: Super Contributor
timestamp: September 25, 2015, 08:13:14 pm
content: Several of the Casio scientific calculators (eg fx-992) have an "engineering" mode in which they will display symbolically the exponent. I find it more of a hindrance than a help, but it's got to be easier and less error-prone than counting 14 digits.

author: LabSpokane
author_rank: Super Contributor
timestamp: September 25, 2015, 08:13:49 pm
content: You're like me. Just remember milli micro nano pico and each one adds 10^-3. I made a lot of crib notes on my tests at first before I answered questions. Made it less error prone.

author: JacquesBBB
author_rank: Frequent Contributor
timestamp: September 25, 2015, 08:15:22 pm
content: Quote from: Flump on September 25, 2015, 07:51:10 pmIf your problem is for an exam question, you certainly do not need 14 digits accuracy.Most exam question are made so minimal accuracy (9 digits ) is already far too much.The most important is to have a good idea of the order of magnitude of the result,that is 1 digit accuracy.This is well illustrated by the example you show

author: Stray Electron
author_rank: Super Contributor
timestamp: September 25, 2015, 08:18:25 pm
content: The HP-41 is the most accurate that I know of and it accurately stores and calculates 12 significant digits. It uses 56 bits internally. All numbers are stored in scientific format. IIRC four bits (1 nibble) is used to store the sign of the exponent and the mantissa; and also to tell the calculator if the data is a number or Alpha data. Two nibbles are used to store the exponent. The remaining 12 nibbles (28 bits) store 12 significant digits. The significant digits are stored as BCD and math is performed in that manner to prevent rounding errors that are inherent with binary and fractions. Most or all of HP calculators up to that time including the big desk top models like the 9825 operated in the same manner. I'm not sure how the later models stored numbers but the 48GX and the like may have even higher resolution. HP usually used calculated values for constants like Pi and to generate functions like Sine values instead of using stored values and that took up less memory and was they were generally calculated to more decimal places so the results on HPs were always more accurate than on other brands of calculators.Find a copy of the PPC ROM manual and read it if you're interested in HIGH accuracy calculations. It will detail things that you never even thought of!

author: LabSpokane
author_rank: Super Contributor
timestamp: September 25, 2015, 08:36:21 pm
content: Quote from: JacquesBBB on September 25, 2015, 08:11:41 pmIt may be done as a courtesy to validate computations (which I fully understand), but anyone who submitted a paper to a respected journal and did not apply significant figures would have their paper rejected.

author: nfmax
author_rank: Super Contributor
timestamp: September 25, 2015, 08:46:06 pm
content: It's not that simple - it depends not only on the number of digits you round to, but how you do the rounding. Getting it wrong can leave you with NO significant digits for some computations. Take a look at William Kahan's web site for a critique by one of the floating-point Jedi Masters, for examplehttps://www.cs.berkeley.edu/~wkahan/MathSand.pdf, which although abut dated is still relevant.

author: tggzzz
author_rank: Super Contributor
timestamp: September 25, 2015, 08:56:07 pm
content: Quote from: JacquesBBB on September 25, 2015, 08:15:22 pmI remember the first exams were calculators (i.e. not slide rules) were allowed, back in '76. There was one numerical question thatrequireda calculator even though the inputs and results were only required to 2 sig figs. The university staff put the question in to see which students would recognise that a slide rule was insufficient, and quite a few of us fell into their carefully prepared trap. No me, I'm pleased to say.What was the question? Given an inverting amplifer with a gain of 10 made from an opamp with open loop gain 10^5 and input voltage of 0.1V, what are all the node voltages?

author: apis
author_rank: Super Contributor
timestamp: September 25, 2015, 09:10:04 pm
content: I just got the Casio fx-991EX (it's relatively cheap). It display 10 significant digits but the manual says it uses 15 digits internally. Floating point that is, so you don't need 10 digits to display nano-values, i.e. it displays x.xxxxxxxxx * 10^xx (e.g. 2*10^-12 or if in "engineering symbol mode": 200 f). My much older calculators all use floating point as well. If I ever needed higher precision I'd use a computer.EDIT: That is, I suspect you just need a "scientific calculator", one that does floating point calculation.

author: JacquesBBB
author_rank: Frequent Contributor
timestamp: September 25, 2015, 09:12:21 pm
content: Quote from: LabSpokane on September 25, 2015, 08:36:21 pmWrong again. For the same reasons.look for example to table 4of the supplementary data of this Nature paperhttp://www.nature.com/nature/journal/v459/n7248/extref/nature08096-s1.pdfAll data are given up to computer accuracy (17 digits) which is far more precise than the real accuracy of these data.The paper has been published in one of the most renown journal (Nature).

author: pelule
author_rank: Frequent Contributor
timestamp: September 25, 2015, 09:14:45 pm
content: How about a Windows based tablet?Is that allowed during the examina. At my time only slide rule was allowed. It's a long time ago.

author: LabSpokane
author_rank: Super Contributor
timestamp: September 25, 2015, 09:23:38 pm
content: Quote from: JacquesBBB on September 25, 2015, 09:12:21 pmAnd published as a table for *input* into a model, not as a result. My point exactly. I'm glad we agree.

author: tom66
author_rank: Super Contributor
timestamp: September 25, 2015, 09:55:16 pm
content: Quote from: Flump on September 25, 2015, 07:51:10 pmIf you cannot understand scientific notation then you will struggle in future engineering professions even if you can pass this exam.Think of scientific notation like the unit. pW = 10-12, so you can just write that as 0.02x10-12or better 2x10-14To convert to the nearest engineering notation increase the exponent by 1 and multiply the mantissa (decimal part) by 10 until the exponent is divisible by 3 and the mantissa is sufficient in size (prefer to be in range 1..10)For example: 0.05x10-7-> 0.5x10-8-> 5x10-9and you know that 10-9is nano so the SI multiplier is "n" or nano.I was taught: My Million New Ponies are Fancy... (Milli Micro Nano Pico Femto)

author: apis
author_rank: Super Contributor
timestamp: September 25, 2015, 10:06:40 pm
content: The easiest way I know of for understanding scientific notation is that the exponent just means how many digits the decimal point has been moved to the left or to the right. For example 0.0012 is the same as 1.2x10-3, i.e. take 1.2 and move the decimal three steps to the right to get the number in normal decimal notation. Negative exponent for small number and positive a large.

author: LabSpokane
author_rank: Super Contributor
timestamp: September 25, 2015, 11:24:42 pm
content: Quote from: JacquesBBB on September 25, 2015, 09:12:21 pmHi Jacques,If it makes you feel any better, I am currently discussing / debating this issue with my wife, who has been published in Nature.

author: vk6zgo
author_rank: Super Contributor
timestamp: September 26, 2015, 03:48:06 am
content: Quote from: tom66 on September 25, 2015, 09:55:16 pmThe great thing about Scientific (& Engineering) Notation is that you can calculate the answer to such questions as the one you postedin your head.Most calculators have Scientic Notation entry functions,& many will convert from decimals to SN.Get one like that,play for a while till you learn how to use SN.Engineering NotationIn Engineering,the names of various measures go in steps of10^3,or 10^-3,as in:volt,kilovolt,Megavolt & so on,going up,& volt,millivolt,microvolt,nanovolt,picovolt,etc going down.Because of this,such values as 10^5 volts is read as 100kV.You need to become familiar with this form of Notation,as otherwise you will find yourself agonising over questions which are worth at best,5 marks,burning exam time & failing.Believe me---I've been there!

author: IanB
author_rank: Super Contributor
timestamp: September 26, 2015, 04:34:55 am
content: Quote from: Flump on September 25, 2015, 07:51:10 pmYou've heard this already by others, but I will repeat it for good measure. You are going to have to work on scientific notation until you get it. There is no choice if you want to progress in any scientific or technical field.QuoteHowever, the good news about this question is that scientific notation is not required. We use the formula P = V²/R and plug in the numbers. We should learn and remember the following table:Giga- = 1 000 000 000Mega- = 1 000 000kilo- = 1 000milli- = 1/1000micro- = 1/1 000 000nano- = 1/1 000 000 000pico- = 1/1 000 000 000 000From this table we see that "micro- times micro- equals pico-", so the result will be 1 pico- divided by 50, which is 0.02 picowatts.No calculator is (or should be) required.

author: kwass
author_rank: Frequent Contributor
timestamp: September 26, 2015, 04:47:19 am
content: The HP-30S has 24 digit internal precision. It's no longer made but it's not hard to find for around $10. Here are the specs:http://www.calculatorsource.com/hp-30s.html

author: cs.dk
author_rank: Unknown
timestamp: September 26, 2015, 06:07:11 am
content: Quote from: alsetalokin4017 on September 25, 2015, 05:40:16 pmThats weird, i've got another result on my TI-89.Can someone explain why the dedicated pi button gives another result than 22/7?2,567x(pi) = 8,064468341772,567x(22/7) = 8,06771428571EDIT: Windows 10 calculator gives this result; 8,0666674566225120984005294152468Why so big difference?

author: retrolefty
author_rank: Super Contributor
timestamp: September 26, 2015, 06:16:24 am
content: Quote from: LabSpokane on September 25, 2015, 05:24:20 pmU.S national debt in pennies?

author: ataradov
author_rank: Super Contributor
timestamp: September 26, 2015, 06:25:32 am
content: Quote from: cs.dk on September 26, 2015, 06:07:11 amBecause Pi != 22/7.Quote from: cs.dk on September 26, 2015, 06:07:11 amIf Windows 10 really gives that result, then throw it away and its calculator.

author: hamster_nz
author_rank: Super Contributor
timestamp: September 26, 2015, 06:40:35 am
content: Quote from: cs.dk on September 26, 2015, 06:07:11 amFWIW, 377?120 is a better approximation of PI2,567x(377/120) = 8,064658333333333A better and more easily remembered approximation is ""How I wish I could enumerate pi". Accurate to to 6 decimal places..

author: cs.dk
author_rank: Unknown
timestamp: September 26, 2015, 06:43:24 am
content: Quote from: hamster_nz on September 26, 2015, 06:40:35 amI just googled around.. Pi is not 22/7, as far as i can see. One stated that 355/113 should be close.

author: ataradov
author_rank: Super Contributor
timestamp: September 26, 2015, 06:47:09 am
content: Quote from: cs.dk on September 26, 2015, 06:43:24 amPi is not any rational fraction, Pi is an irrational number.Quote from: cs.dk on September 26, 2015, 06:43:24 amClose for what purposes? Calculating trajectories of rockets? I don't think so.

author: cs.dk
author_rank: Unknown
timestamp: September 26, 2015, 06:50:12 am
content: Quote from: ataradov on September 26, 2015, 06:47:09 amAs in - closer than 22/7, and relative easy to remember.

author: SeanB
author_rank: Super Contributor
timestamp: September 26, 2015, 06:59:00 am
content: 22/7 is an approximation for pi, good to 3 digits after the decimal, but it is NOT pi. Good enough for building a wall or tank. pi is an irrational number, look it up....https://en.wikipedia.org/wiki/Pi

author: vk6zgo
author_rank: Super Contributor
timestamp: September 26, 2015, 08:19:59 am
content: In quite a few calculations3is "near as dammit" a good enough approximation.People get all "thingy" about pi,but still use many other approximations.For instance,the speed of light isn't really 300,000,000 metres/sec ----just "near as dammit".

author: tggzzz
author_rank: Super Contributor
timestamp: September 26, 2015, 08:38:48 am
content: Quote from: vk6zgo on September 26, 2015, 08:19:59 amFor most of my purposes, the speed of light is 200e6m/s or 225e6m/s. But then I only use easily obtainable and cheap materials.

author: SteveLy
author_rank: Regular Contributor
timestamp: September 26, 2015, 09:20:12 am
content: Sounds like OP wants more digits to avoid powers of 10 scientific notation; wants answers like eg:0.000000000024Instead of:2.4e-11Definitely not a good idea. You'll run into more trouble than you'll circumvent. Just find some exercises and spend a few hours practicing using scientific and engineering notation (including switching back and forth between prefixes T, G, M, k,..., f and powers of 10). It'll save you a lot of hassle.

author: wraper
author_rank: Unknown
timestamp: September 26, 2015, 09:48:55 am
content: Quote from: Flump on September 25, 2015, 07:51:10 pmFrankly saying this is just ridiculous. Heck you don't even need a calculator for that question BTW.What so hard in scientific notation? It's just how many zeroes you have after (or before) the comma. It is even easier than simple numbers, because you already know digit count and don't need to count them.For example x * 10-12- pico, like picofarads, picowatts, picovolts. x * 10-9- nano, x * 10-6- micro, x * 10-3milli.

author: SteveLy
author_rank: Regular Contributor
timestamp: September 26, 2015, 10:11:18 am
content: @wraper: like everything else, it's easyonce you get it. Scientific notation especially in combination with prefixes (m, ?, n etc) can be confusing for beginner students.@OP: The most useful thing you need to learn and practice until it becomes second nature is that you can add exponents when you multiply powers of 10, e.g..:10a×10b= 10a+b;10a×10-b= 10a-b.Here is an example of the type of problem that stumps many first year physics students:Q:What's 4.5 × 10-10V in nV? 20-30% of beginning first years will answer 45 nV, which is of course wrong. Here is one way to get the answer systematically using the fact that1n = 10-9,i.e.:1n × 109= 1.A:Solution in excruciating detail:4.5 × 10-10V= 4.5 × (1) × 10-10V= 4.5 × (1n × 109) × 10-10V= 4.5 × 1n × 109-10V= 4.5 × 1n × 10-1V= 4.5 × 10-1nV= 4.5 × 0.1 nV= 0.45 nVAlternatively (and a bit more quickly) you can proceed like this:4.5 × 10-10V= 4.5 × 10-1-9V= 4.5 × 10-1× 10-9V= 4.5 × 0.1 × nV= 0.45 nVOf course with a little bit of practice you can do all that in a single step almost without thinking. But when you're starting out it helps to break the calculation up into very simple rudimentary steps.

author: SteveLy
author_rank: Regular Contributor
timestamp: September 26, 2015, 10:44:53 am
content: @Flump: Here are some additional rules you need to know and understand:100= 11/10a= 10-a10a/ 10b= 10a-b(10a)b= 10a×bLet me go through the example problem you quoted:Q: R = 50 Ohm, V = 1uV, P = ?A: Combining Ohm's law: V = I×R, and the basic equation for power: P = V×I, we get:P = V2/R= (1uV)2/(50Ohm)= (10-6)2/ (5×10) W, using 1u = 10-6;= (10-12/ 101) × (1/5) W; using (10a)b= 10a×b;= 10-12-1× 0.2 W; using 10a/ 10b= 10a-b;= 10-13× 10-1× 2 W; using 0.1 = 10-1;= 10-14× 2 W; using 10a× 10b= 10a+b;= 2 × 10-2× 10-12W; using same rule again in reverse and going for 10-12= 1p;= 2 × 0.01 pW; using 10-2= 0.01;= 0.02 pWYou've got to practice doing it like this first. Baby step by baby step. It looks like a crazy amount of work but you only do it like this for a little while for practice. Keep at it and you'll quickly become proficient and will be able to do calculations like these in a couple of steps.

author: JacquesBBB
author_rank: Frequent Contributor
timestamp: September 26, 2015, 11:12:24 am
content: Quote from: SteveLy on September 26, 2015, 10:11:18 amI would rather write it like :V = 109nVthus4.5 × 10-10V= 4.5 × 10-10x 109nV= 4.5 × 10-10+9nV= 4.5 × 10-1nV= 0.45 nV

author: Delta
author_rank: Super Contributor
timestamp: September 26, 2015, 11:17:50 am
content: Flump, really mate you need to get your head around engineering notation. It is so handy.If you're doing your calculations without it, 0.000000000076 x 0.000052 for example, you WILL miss or add zeroes sometimes.

author: IanB
author_rank: Super Contributor
timestamp: September 26, 2015, 11:21:32 am
content: Quote from: SteveLy on September 26, 2015, 10:11:18 amThat really seems like a very laborious way of solving the problem. Also, it makes extensive use of "rules" rather than helping with conceptual understanding.A more mathematical way of understanding the problem would be to recognize that,4.5 x 10-10= "4.5 with decimal shifted ten places to the left"From this starting point we can shift the decimal left or right as long as we keep count of the shifts, so that:"4.5 with decimal shiftedtenplaces to the left" = "0.45 with decimal shiftednineplaces to the left"Or rather more concisely:4.5 x 10-10V = 0.45 x 10-9V = 0.45 nVShifting the decimal directly gets to the concept of scale ( <-- smaller . larger --> ) and does not require error-prone algebraic manipulations and rules for combining exponents.Hemant Mehta here has some insight into why this kind of thinking is important:http://www.patheos.com/blogs/friendlyatheist/2015/09/21/the-dad-who-wrote-a-check-using-common-core-math-doesnt-know-what-hes-talking-about/

author: SteveLy
author_rank: Regular Contributor
timestamp: September 26, 2015, 11:37:45 am
content: Sure, for a simple problem like this it's overkill, but in general, manipulating exponents is something one needs to master to be able to handle more complicated problems, where shifting decimal points can get very tedious and error prone.One "trick" that can always be applied is to multiply an answer by 1. Then choose the representation of 1 in the desired units: 1 = 10-6M = ... = 109n = 1012p. But that's just one of many ways of doing things. It seems to be helpful for beginners when they are stumped: 'how do I introduce the desired units into my expression'?ps. I've also encountered many students who just don't get the 'shifting the decimal point' idea, i.e., they often end up shifting the wrong way in practice despite seemingly understanding the basic principle. Then I get them to break up everything into powers of 10 and then they get it right.

author: HighVoltage
author_rank: Super Contributor
timestamp: September 26, 2015, 11:55:33 am
content: for those who can not "get" the scientific notation and need lots of decimal places, there is the calculator APP that comes standard with the iPhone and has 16 digits.

author: RickBrant
author_rank: Unknown
timestamp: September 26, 2015, 12:19:07 pm
content: The comments on scientific notation and the SI prefixes (milli, etc.) reminds me of something from one of Neil deGrasse Tyson's books:Quote

author: RickBrant
author_rank: Unknown
timestamp: September 26, 2015, 12:45:25 pm
content: Quote from: cs.dk on September 26, 2015, 06:07:11 amThat's not the result I get on my Win10 machine. I get8.0644683417649992431336055648785the same thing you got on your TI-89, except in your last shown decimal place. Your calculator is likely maintaining more digits internally than it's displaying, so "rounding" is not necessarily happening based just on the digit just to the right of the last displayed.Win 8.1 calc gives the same result.HP 15C says 8.064468343. Interesting.

author: Galenbo
author_rank: Super Contributor
timestamp: September 26, 2015, 12:55:50 pm
content: Quote from: cs.dk on September 26, 2015, 06:50:12 amQuote from: cs.dk on September 26, 2015, 06:50:12 amWhy is 355/113= easyer to remember than 3.141592 for you?

author: RickBrant
author_rank: Unknown
timestamp: September 26, 2015, 01:00:01 pm
content: Quote from: Stray Electron on September 25, 2015, 08:18:25 pmA quibble, but I think you mean "roundingdifferences." Every number base has some fractions it can't represent exactly. e.g. you can't express "1/3" perfectly in decimal, either. The most famous for binary is "1/10", and by extension "1/100". So binary floating point is shunned by e.g. accountants, because they want the computer to give the same results as hand calculation or a desk adding machine would. But if we had coins that represented a third of a dollar, and we needed to express that quantity exactly, they wouldn't like decimal f.p. either.Hmm: The more prime factors of your number base, the more fractions it can express without repeating digits. Is that right? I'm not a number theory person. But imagine the possibilites of base 60Fun fact: You can express the value of piexactlywith just two digits. You just have to usebase pi.

author: RickBrant
author_rank: Unknown
timestamp: September 26, 2015, 01:01:31 pm
content: Quote from: Galenbo on September 26, 2015, 12:55:50 pmIt's the pattern. Three and two fives, two ones and a three. (And with proper rounding, shouldn't that be 3.141593? The next digit after the 2 is a 6....)

author: SteveLy
author_rank: Regular Contributor
timestamp: September 26, 2015, 05:20:36 pm
content: Quote from: RickBrant on September 26, 2015, 12:19:07 pmYeah, that's a good one.Quote from: RickBrant on September 26, 2015, 12:45:25 pm8.0644683417649992431336055648784839037341338481958966424426827684541647149366984994781653966532145130--- using bc, arbitrary precision calculator (standard Linux issue), with scale set to 100; for when you want pointless amount of precision. :-P

author: electr_peter
author_rank: Unknown
timestamp: September 26, 2015, 07:17:32 pm
content: 12-15 digits calculators are useful for accountants (where they deal with both 1 cent items and millions/billions/trillions, etc.). Some currencies have very low value for single denomination, keep that in mind.As for scientific purposes, there is very little use in this high multiple digit precision except for very small angles in sin/cos/tan calculations and for keeping track of calculation steps (so you know where things go wrong). Otherwise it is not very useful - use a computer instead to calculate with arbitrary precision if you need that.

author: RickBrant
author_rank: Unknown
timestamp: September 26, 2015, 08:59:00 pm
content: Another place where high precision is relevant is in calculations of fractal systems. "Sensitive dependence on initial conditions" and all that.

author: Galenbo
author_rank: Super Contributor
timestamp: September 27, 2015, 06:24:51 pm
content: Quote from: RickBrant on September 26, 2015, 01:01:31 pmSo 1t3 2t5 / 2t1 1t3 = is easyer than 3.141592 ?And I thoughtmymind was strange....