Percentual change from 0











up vote
0
down vote

favorite












How to calculate the procentual change with respect to 0.



For example: The old value is 0, while the new value is 10.



How to calculate the procentual change in this case?










share|cite|improve this question
























  • Isn't it always $100$% since the previous number is $0$? Edit: Oh, too late
    – NotEinstein
    Dec 6 at 7:50








  • 1




    It's undefined. There can be no relative change from $0$. The absolute change is $10$ ($10-0 = 10$).
    – Eff
    Dec 6 at 8:31












  • (I forgot about the initial value in my previous comment, so here’s the correction.) $frac{v_2-v_1}{v_1}$ is undefined for $v_1 = 0$. If you have $v_1 = 2$ and $v_2 = 3$, for instance, you get a percentage change of $50$%. In other words, $2$ added to $50$% of itself gives $3$. Can $0$ added to any percentage of itself give a non-zero number?
    – KM101
    Dec 6 at 8:41












  • The "percentage change" number isn't that useful when your number is hovering around zero anyway.
    – James
    Dec 6 at 13:44















up vote
0
down vote

favorite












How to calculate the procentual change with respect to 0.



For example: The old value is 0, while the new value is 10.



How to calculate the procentual change in this case?










share|cite|improve this question
























  • Isn't it always $100$% since the previous number is $0$? Edit: Oh, too late
    – NotEinstein
    Dec 6 at 7:50








  • 1




    It's undefined. There can be no relative change from $0$. The absolute change is $10$ ($10-0 = 10$).
    – Eff
    Dec 6 at 8:31












  • (I forgot about the initial value in my previous comment, so here’s the correction.) $frac{v_2-v_1}{v_1}$ is undefined for $v_1 = 0$. If you have $v_1 = 2$ and $v_2 = 3$, for instance, you get a percentage change of $50$%. In other words, $2$ added to $50$% of itself gives $3$. Can $0$ added to any percentage of itself give a non-zero number?
    – KM101
    Dec 6 at 8:41












  • The "percentage change" number isn't that useful when your number is hovering around zero anyway.
    – James
    Dec 6 at 13:44













up vote
0
down vote

favorite









up vote
0
down vote

favorite











How to calculate the procentual change with respect to 0.



For example: The old value is 0, while the new value is 10.



How to calculate the procentual change in this case?










share|cite|improve this question















How to calculate the procentual change with respect to 0.



For example: The old value is 0, while the new value is 10.



How to calculate the procentual change in this case?







average






share|cite|improve this question















share|cite|improve this question













share|cite|improve this question




share|cite|improve this question








edited Dec 6 at 9:15









nippon

335212




335212










asked Dec 6 at 7:46









Abhijit Bendigiri

71




71












  • Isn't it always $100$% since the previous number is $0$? Edit: Oh, too late
    – NotEinstein
    Dec 6 at 7:50








  • 1




    It's undefined. There can be no relative change from $0$. The absolute change is $10$ ($10-0 = 10$).
    – Eff
    Dec 6 at 8:31












  • (I forgot about the initial value in my previous comment, so here’s the correction.) $frac{v_2-v_1}{v_1}$ is undefined for $v_1 = 0$. If you have $v_1 = 2$ and $v_2 = 3$, for instance, you get a percentage change of $50$%. In other words, $2$ added to $50$% of itself gives $3$. Can $0$ added to any percentage of itself give a non-zero number?
    – KM101
    Dec 6 at 8:41












  • The "percentage change" number isn't that useful when your number is hovering around zero anyway.
    – James
    Dec 6 at 13:44


















  • Isn't it always $100$% since the previous number is $0$? Edit: Oh, too late
    – NotEinstein
    Dec 6 at 7:50








  • 1




    It's undefined. There can be no relative change from $0$. The absolute change is $10$ ($10-0 = 10$).
    – Eff
    Dec 6 at 8:31












  • (I forgot about the initial value in my previous comment, so here’s the correction.) $frac{v_2-v_1}{v_1}$ is undefined for $v_1 = 0$. If you have $v_1 = 2$ and $v_2 = 3$, for instance, you get a percentage change of $50$%. In other words, $2$ added to $50$% of itself gives $3$. Can $0$ added to any percentage of itself give a non-zero number?
    – KM101
    Dec 6 at 8:41












  • The "percentage change" number isn't that useful when your number is hovering around zero anyway.
    – James
    Dec 6 at 13:44
















Isn't it always $100$% since the previous number is $0$? Edit: Oh, too late
– NotEinstein
Dec 6 at 7:50






Isn't it always $100$% since the previous number is $0$? Edit: Oh, too late
– NotEinstein
Dec 6 at 7:50






1




1




It's undefined. There can be no relative change from $0$. The absolute change is $10$ ($10-0 = 10$).
– Eff
Dec 6 at 8:31






It's undefined. There can be no relative change from $0$. The absolute change is $10$ ($10-0 = 10$).
– Eff
Dec 6 at 8:31














(I forgot about the initial value in my previous comment, so here’s the correction.) $frac{v_2-v_1}{v_1}$ is undefined for $v_1 = 0$. If you have $v_1 = 2$ and $v_2 = 3$, for instance, you get a percentage change of $50$%. In other words, $2$ added to $50$% of itself gives $3$. Can $0$ added to any percentage of itself give a non-zero number?
– KM101
Dec 6 at 8:41






(I forgot about the initial value in my previous comment, so here’s the correction.) $frac{v_2-v_1}{v_1}$ is undefined for $v_1 = 0$. If you have $v_1 = 2$ and $v_2 = 3$, for instance, you get a percentage change of $50$%. In other words, $2$ added to $50$% of itself gives $3$. Can $0$ added to any percentage of itself give a non-zero number?
– KM101
Dec 6 at 8:41














The "percentage change" number isn't that useful when your number is hovering around zero anyway.
– James
Dec 6 at 13:44




The "percentage change" number isn't that useful when your number is hovering around zero anyway.
– James
Dec 6 at 13:44










2 Answers
2






active

oldest

votes

















up vote
5
down vote













When the previous value $x$ is non-zero, the formula is $$frac{y-x}{x} times 100 %$$



Now, remember that we are not supposed to divide by $0$.



It should be undefined.



If it is defined and we claim that it is $r$, a real number, given the percentage change and the current value, we can't recover $x$ to be $0$ and we might misguide ourselves to think that $x$ is some non-zero number.



$$frac{y}x =1+frac{r}{100}$$



$$x=frac{y}{1+frac{r}{100}}$$



If you have to put down something, perhaps put down a symbol to indicate that the previous number is zero.






share|cite|improve this answer





















  • "perhaps put down a symbol to..." - and I'd suggest to use the symbol ∞. Just remember that this is not a number, it's just a symbol that indicated the previous number is zero. Which should be clear to a mathematician, but perhaps not to a casual reader.
    – Radovan Garabík
    Dec 6 at 14:27


















up vote
4
down vote













While the other answer by Siong Thye Goh is right, I want to present a slightly more intuitive approach.



The "percent change" of $x$ to $y$ is essentially saying, for some number $p$,



$$x + (p% text{ of } x) = y$$



For example, the percentage change of $2$ to $5$ can be calculated via the method Siong mentioned:



$$frac{5-2}{2} times 100% = frac{3}{2} times 100% = 150%$$



We can equivalently state what this means by



$$2 + (150% text{ of } 2) = 5$$



Since $150%$ of $2$ is given by $150% cdot 2 = 1.5 cdot 2 = 3$, this idea becomes somewhat clear, this idea being that



$$x + (p% text{ of } x) = y ;;; Leftrightarrow ;;; frac{y-x}{x} = p$$



i.e. this intuitive approach is analogous to the formula you usually get told a la what Siong noted.



So we ask: what if $x = 0$, and $y neq 0$? Well, we have



$$0 + (p% text{ of } 0) = y neq 0$$



Okay, but $0$ plus anything is just that thing, and any percentage of $0$ is $0$, and $0+0=0$. Thus, we get



$$0 = y neq 0$$



i.e. a nonsensical answer, and our $p$ is irrelevant here. No matter what $p$ is, there is always this contradiction. Similarly, if $y=0$, then we get a true statement instead but it's true for all possible values of $p$ instead.



So in that sense, we say that the percentage change starting from $0$ is nonsensical. Either you have a contradictory answer or just a plain true statement, regardless of your $p$ - $p$ becomes irrelevant in both cases. So it only makes sense to say that the percentage change $p$ is undefined.






share|cite|improve this answer





















    Your Answer





    StackExchange.ifUsing("editor", function () {
    return StackExchange.using("mathjaxEditing", function () {
    StackExchange.MarkdownEditor.creationCallbacks.add(function (editor, postfix) {
    StackExchange.mathjaxEditing.prepareWmdForMathJax(editor, postfix, [["$", "$"], ["\\(","\\)"]]);
    });
    });
    }, "mathjax-editing");

    StackExchange.ready(function() {
    var channelOptions = {
    tags: "".split(" "),
    id: "69"
    };
    initTagRenderer("".split(" "), "".split(" "), channelOptions);

    StackExchange.using("externalEditor", function() {
    // Have to fire editor after snippets, if snippets enabled
    if (StackExchange.settings.snippets.snippetsEnabled) {
    StackExchange.using("snippets", function() {
    createEditor();
    });
    }
    else {
    createEditor();
    }
    });

    function createEditor() {
    StackExchange.prepareEditor({
    heartbeatType: 'answer',
    convertImagesToLinks: true,
    noModals: true,
    showLowRepImageUploadWarning: true,
    reputationToPostImages: 10,
    bindNavPrevention: true,
    postfix: "",
    imageUploader: {
    brandingHtml: "Powered by u003ca class="icon-imgur-white" href="https://imgur.com/"u003eu003c/au003e",
    contentPolicyHtml: "User contributions licensed under u003ca href="https://creativecommons.org/licenses/by-sa/3.0/"u003ecc by-sa 3.0 with attribution requiredu003c/au003e u003ca href="https://stackoverflow.com/legal/content-policy"u003e(content policy)u003c/au003e",
    allowUrls: true
    },
    noCode: true, onDemand: true,
    discardSelector: ".discard-answer"
    ,immediatelyShowMarkdownHelp:true
    });


    }
    });














    draft saved

    draft discarded


















    StackExchange.ready(
    function () {
    StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fmath.stackexchange.com%2fquestions%2f3028194%2fpercentual-change-from-0%23new-answer', 'question_page');
    }
    );

    Post as a guest















    Required, but never shown

























    2 Answers
    2






    active

    oldest

    votes








    2 Answers
    2






    active

    oldest

    votes









    active

    oldest

    votes






    active

    oldest

    votes








    up vote
    5
    down vote













    When the previous value $x$ is non-zero, the formula is $$frac{y-x}{x} times 100 %$$



    Now, remember that we are not supposed to divide by $0$.



    It should be undefined.



    If it is defined and we claim that it is $r$, a real number, given the percentage change and the current value, we can't recover $x$ to be $0$ and we might misguide ourselves to think that $x$ is some non-zero number.



    $$frac{y}x =1+frac{r}{100}$$



    $$x=frac{y}{1+frac{r}{100}}$$



    If you have to put down something, perhaps put down a symbol to indicate that the previous number is zero.






    share|cite|improve this answer





















    • "perhaps put down a symbol to..." - and I'd suggest to use the symbol ∞. Just remember that this is not a number, it's just a symbol that indicated the previous number is zero. Which should be clear to a mathematician, but perhaps not to a casual reader.
      – Radovan Garabík
      Dec 6 at 14:27















    up vote
    5
    down vote













    When the previous value $x$ is non-zero, the formula is $$frac{y-x}{x} times 100 %$$



    Now, remember that we are not supposed to divide by $0$.



    It should be undefined.



    If it is defined and we claim that it is $r$, a real number, given the percentage change and the current value, we can't recover $x$ to be $0$ and we might misguide ourselves to think that $x$ is some non-zero number.



    $$frac{y}x =1+frac{r}{100}$$



    $$x=frac{y}{1+frac{r}{100}}$$



    If you have to put down something, perhaps put down a symbol to indicate that the previous number is zero.






    share|cite|improve this answer





















    • "perhaps put down a symbol to..." - and I'd suggest to use the symbol ∞. Just remember that this is not a number, it's just a symbol that indicated the previous number is zero. Which should be clear to a mathematician, but perhaps not to a casual reader.
      – Radovan Garabík
      Dec 6 at 14:27













    up vote
    5
    down vote










    up vote
    5
    down vote









    When the previous value $x$ is non-zero, the formula is $$frac{y-x}{x} times 100 %$$



    Now, remember that we are not supposed to divide by $0$.



    It should be undefined.



    If it is defined and we claim that it is $r$, a real number, given the percentage change and the current value, we can't recover $x$ to be $0$ and we might misguide ourselves to think that $x$ is some non-zero number.



    $$frac{y}x =1+frac{r}{100}$$



    $$x=frac{y}{1+frac{r}{100}}$$



    If you have to put down something, perhaps put down a symbol to indicate that the previous number is zero.






    share|cite|improve this answer












    When the previous value $x$ is non-zero, the formula is $$frac{y-x}{x} times 100 %$$



    Now, remember that we are not supposed to divide by $0$.



    It should be undefined.



    If it is defined and we claim that it is $r$, a real number, given the percentage change and the current value, we can't recover $x$ to be $0$ and we might misguide ourselves to think that $x$ is some non-zero number.



    $$frac{y}x =1+frac{r}{100}$$



    $$x=frac{y}{1+frac{r}{100}}$$



    If you have to put down something, perhaps put down a symbol to indicate that the previous number is zero.







    share|cite|improve this answer












    share|cite|improve this answer



    share|cite|improve this answer










    answered Dec 6 at 7:55









    Siong Thye Goh

    97.4k1463116




    97.4k1463116












    • "perhaps put down a symbol to..." - and I'd suggest to use the symbol ∞. Just remember that this is not a number, it's just a symbol that indicated the previous number is zero. Which should be clear to a mathematician, but perhaps not to a casual reader.
      – Radovan Garabík
      Dec 6 at 14:27


















    • "perhaps put down a symbol to..." - and I'd suggest to use the symbol ∞. Just remember that this is not a number, it's just a symbol that indicated the previous number is zero. Which should be clear to a mathematician, but perhaps not to a casual reader.
      – Radovan Garabík
      Dec 6 at 14:27
















    "perhaps put down a symbol to..." - and I'd suggest to use the symbol ∞. Just remember that this is not a number, it's just a symbol that indicated the previous number is zero. Which should be clear to a mathematician, but perhaps not to a casual reader.
    – Radovan Garabík
    Dec 6 at 14:27




    "perhaps put down a symbol to..." - and I'd suggest to use the symbol ∞. Just remember that this is not a number, it's just a symbol that indicated the previous number is zero. Which should be clear to a mathematician, but perhaps not to a casual reader.
    – Radovan Garabík
    Dec 6 at 14:27










    up vote
    4
    down vote













    While the other answer by Siong Thye Goh is right, I want to present a slightly more intuitive approach.



    The "percent change" of $x$ to $y$ is essentially saying, for some number $p$,



    $$x + (p% text{ of } x) = y$$



    For example, the percentage change of $2$ to $5$ can be calculated via the method Siong mentioned:



    $$frac{5-2}{2} times 100% = frac{3}{2} times 100% = 150%$$



    We can equivalently state what this means by



    $$2 + (150% text{ of } 2) = 5$$



    Since $150%$ of $2$ is given by $150% cdot 2 = 1.5 cdot 2 = 3$, this idea becomes somewhat clear, this idea being that



    $$x + (p% text{ of } x) = y ;;; Leftrightarrow ;;; frac{y-x}{x} = p$$



    i.e. this intuitive approach is analogous to the formula you usually get told a la what Siong noted.



    So we ask: what if $x = 0$, and $y neq 0$? Well, we have



    $$0 + (p% text{ of } 0) = y neq 0$$



    Okay, but $0$ plus anything is just that thing, and any percentage of $0$ is $0$, and $0+0=0$. Thus, we get



    $$0 = y neq 0$$



    i.e. a nonsensical answer, and our $p$ is irrelevant here. No matter what $p$ is, there is always this contradiction. Similarly, if $y=0$, then we get a true statement instead but it's true for all possible values of $p$ instead.



    So in that sense, we say that the percentage change starting from $0$ is nonsensical. Either you have a contradictory answer or just a plain true statement, regardless of your $p$ - $p$ becomes irrelevant in both cases. So it only makes sense to say that the percentage change $p$ is undefined.






    share|cite|improve this answer

























      up vote
      4
      down vote













      While the other answer by Siong Thye Goh is right, I want to present a slightly more intuitive approach.



      The "percent change" of $x$ to $y$ is essentially saying, for some number $p$,



      $$x + (p% text{ of } x) = y$$



      For example, the percentage change of $2$ to $5$ can be calculated via the method Siong mentioned:



      $$frac{5-2}{2} times 100% = frac{3}{2} times 100% = 150%$$



      We can equivalently state what this means by



      $$2 + (150% text{ of } 2) = 5$$



      Since $150%$ of $2$ is given by $150% cdot 2 = 1.5 cdot 2 = 3$, this idea becomes somewhat clear, this idea being that



      $$x + (p% text{ of } x) = y ;;; Leftrightarrow ;;; frac{y-x}{x} = p$$



      i.e. this intuitive approach is analogous to the formula you usually get told a la what Siong noted.



      So we ask: what if $x = 0$, and $y neq 0$? Well, we have



      $$0 + (p% text{ of } 0) = y neq 0$$



      Okay, but $0$ plus anything is just that thing, and any percentage of $0$ is $0$, and $0+0=0$. Thus, we get



      $$0 = y neq 0$$



      i.e. a nonsensical answer, and our $p$ is irrelevant here. No matter what $p$ is, there is always this contradiction. Similarly, if $y=0$, then we get a true statement instead but it's true for all possible values of $p$ instead.



      So in that sense, we say that the percentage change starting from $0$ is nonsensical. Either you have a contradictory answer or just a plain true statement, regardless of your $p$ - $p$ becomes irrelevant in both cases. So it only makes sense to say that the percentage change $p$ is undefined.






      share|cite|improve this answer























        up vote
        4
        down vote










        up vote
        4
        down vote









        While the other answer by Siong Thye Goh is right, I want to present a slightly more intuitive approach.



        The "percent change" of $x$ to $y$ is essentially saying, for some number $p$,



        $$x + (p% text{ of } x) = y$$



        For example, the percentage change of $2$ to $5$ can be calculated via the method Siong mentioned:



        $$frac{5-2}{2} times 100% = frac{3}{2} times 100% = 150%$$



        We can equivalently state what this means by



        $$2 + (150% text{ of } 2) = 5$$



        Since $150%$ of $2$ is given by $150% cdot 2 = 1.5 cdot 2 = 3$, this idea becomes somewhat clear, this idea being that



        $$x + (p% text{ of } x) = y ;;; Leftrightarrow ;;; frac{y-x}{x} = p$$



        i.e. this intuitive approach is analogous to the formula you usually get told a la what Siong noted.



        So we ask: what if $x = 0$, and $y neq 0$? Well, we have



        $$0 + (p% text{ of } 0) = y neq 0$$



        Okay, but $0$ plus anything is just that thing, and any percentage of $0$ is $0$, and $0+0=0$. Thus, we get



        $$0 = y neq 0$$



        i.e. a nonsensical answer, and our $p$ is irrelevant here. No matter what $p$ is, there is always this contradiction. Similarly, if $y=0$, then we get a true statement instead but it's true for all possible values of $p$ instead.



        So in that sense, we say that the percentage change starting from $0$ is nonsensical. Either you have a contradictory answer or just a plain true statement, regardless of your $p$ - $p$ becomes irrelevant in both cases. So it only makes sense to say that the percentage change $p$ is undefined.






        share|cite|improve this answer












        While the other answer by Siong Thye Goh is right, I want to present a slightly more intuitive approach.



        The "percent change" of $x$ to $y$ is essentially saying, for some number $p$,



        $$x + (p% text{ of } x) = y$$



        For example, the percentage change of $2$ to $5$ can be calculated via the method Siong mentioned:



        $$frac{5-2}{2} times 100% = frac{3}{2} times 100% = 150%$$



        We can equivalently state what this means by



        $$2 + (150% text{ of } 2) = 5$$



        Since $150%$ of $2$ is given by $150% cdot 2 = 1.5 cdot 2 = 3$, this idea becomes somewhat clear, this idea being that



        $$x + (p% text{ of } x) = y ;;; Leftrightarrow ;;; frac{y-x}{x} = p$$



        i.e. this intuitive approach is analogous to the formula you usually get told a la what Siong noted.



        So we ask: what if $x = 0$, and $y neq 0$? Well, we have



        $$0 + (p% text{ of } 0) = y neq 0$$



        Okay, but $0$ plus anything is just that thing, and any percentage of $0$ is $0$, and $0+0=0$. Thus, we get



        $$0 = y neq 0$$



        i.e. a nonsensical answer, and our $p$ is irrelevant here. No matter what $p$ is, there is always this contradiction. Similarly, if $y=0$, then we get a true statement instead but it's true for all possible values of $p$ instead.



        So in that sense, we say that the percentage change starting from $0$ is nonsensical. Either you have a contradictory answer or just a plain true statement, regardless of your $p$ - $p$ becomes irrelevant in both cases. So it only makes sense to say that the percentage change $p$ is undefined.







        share|cite|improve this answer












        share|cite|improve this answer



        share|cite|improve this answer










        answered Dec 6 at 8:28









        Eevee Trainer

        2,639221




        2,639221






























            draft saved

            draft discarded




















































            Thanks for contributing an answer to Mathematics Stack Exchange!


            • Please be sure to answer the question. Provide details and share your research!

            But avoid



            • Asking for help, clarification, or responding to other answers.

            • Making statements based on opinion; back them up with references or personal experience.


            Use MathJax to format equations. MathJax reference.


            To learn more, see our tips on writing great answers.





            Some of your past answers have not been well-received, and you're in danger of being blocked from answering.


            Please pay close attention to the following guidance:


            • Please be sure to answer the question. Provide details and share your research!

            But avoid



            • Asking for help, clarification, or responding to other answers.

            • Making statements based on opinion; back them up with references or personal experience.


            To learn more, see our tips on writing great answers.




            draft saved


            draft discarded














            StackExchange.ready(
            function () {
            StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fmath.stackexchange.com%2fquestions%2f3028194%2fpercentual-change-from-0%23new-answer', 'question_page');
            }
            );

            Post as a guest















            Required, but never shown





















































            Required, but never shown














            Required, but never shown












            Required, but never shown







            Required, but never shown

































            Required, but never shown














            Required, but never shown












            Required, but never shown







            Required, but never shown







            Popular posts from this blog

            Сан-Квентин

            8-я гвардейская общевойсковая армия

            Алькесар