How is rearranging 56 x 100 ÷ 8 into 56 ÷8 x100 allowed by the commutative property?












1












$begingroup$


So according to the commutative property for multiplication:



$a * b = b * a$



However this does not hold for division



$a ÷ b$ $!= b ÷a$



Why is it that in the following case:



$56 * 100 ÷ 8 = 56 ÷ 8* 100$



It seems like division is breaking the rule. There is something I am misunderstanding here.



Is it because $a*b÷c=a÷c*b$ is allowed since $b÷c$ are not being rearranged so that $c÷b$?



If this is the case are you allowed to rearrange values in equations so long as no values have the form $a ÷ b$ $= b ÷a$ and $a - b$ $= b -a$ ?










share|cite|improve this question











$endgroup$

















    1












    $begingroup$


    So according to the commutative property for multiplication:



    $a * b = b * a$



    However this does not hold for division



    $a ÷ b$ $!= b ÷a$



    Why is it that in the following case:



    $56 * 100 ÷ 8 = 56 ÷ 8* 100$



    It seems like division is breaking the rule. There is something I am misunderstanding here.



    Is it because $a*b÷c=a÷c*b$ is allowed since $b÷c$ are not being rearranged so that $c÷b$?



    If this is the case are you allowed to rearrange values in equations so long as no values have the form $a ÷ b$ $= b ÷a$ and $a - b$ $= b -a$ ?










    share|cite|improve this question











    $endgroup$















      1












      1








      1





      $begingroup$


      So according to the commutative property for multiplication:



      $a * b = b * a$



      However this does not hold for division



      $a ÷ b$ $!= b ÷a$



      Why is it that in the following case:



      $56 * 100 ÷ 8 = 56 ÷ 8* 100$



      It seems like division is breaking the rule. There is something I am misunderstanding here.



      Is it because $a*b÷c=a÷c*b$ is allowed since $b÷c$ are not being rearranged so that $c÷b$?



      If this is the case are you allowed to rearrange values in equations so long as no values have the form $a ÷ b$ $= b ÷a$ and $a - b$ $= b -a$ ?










      share|cite|improve this question











      $endgroup$




      So according to the commutative property for multiplication:



      $a * b = b * a$



      However this does not hold for division



      $a ÷ b$ $!= b ÷a$



      Why is it that in the following case:



      $56 * 100 ÷ 8 = 56 ÷ 8* 100$



      It seems like division is breaking the rule. There is something I am misunderstanding here.



      Is it because $a*b÷c=a÷c*b$ is allowed since $b÷c$ are not being rearranged so that $c÷b$?



      If this is the case are you allowed to rearrange values in equations so long as no values have the form $a ÷ b$ $= b ÷a$ and $a - b$ $= b -a$ ?







      arithmetic






      share|cite|improve this question















      share|cite|improve this question













      share|cite|improve this question




      share|cite|improve this question








      edited 41 mins ago







      Sphygmomanometer

















      asked 43 mins ago









      SphygmomanometerSphygmomanometer

      717




      717






















          4 Answers
          4






          active

          oldest

          votes


















          1












          $begingroup$

          Notice that you have always $div 8$, no matter the order of the other terms. You don't divide by a different number. It might help to think $div c$ as a multiplication with $d=1/c$. Then everything would look easier:
          $$atimes bdiv c=atimes btimes d=atimes dtimes b=adiv ctimes b$$






          share|cite|improve this answer









          $endgroup$





















            2












            $begingroup$

            The non-zero real numbers form an abelian group under multiplication. The notation $adiv b$ is shorthand for $ab^{-1}$.



            So $ab^{-1}ne ba^{-1}$ but $56times100 times8^{-1}=56times 8^{-1}times 100$






            share|cite|improve this answer









            $endgroup$





















              1












              $begingroup$

              Hope this makes sense.



              $$ atimes b ÷ c $$



              $$=atimesdfrac{b}{c}$$



              $$=atimes btimesdfrac{1}{c}$$



              $$=(atimesdfrac{1}{c})times b$$



              $$=dfrac{a}{c}times b$$



              $$=a÷ctimes b$$






              share|cite|improve this answer








              New contributor




              Aditya is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
              Check out our Code of Conduct.






              $endgroup$





















                1












                $begingroup$

                Because division is the inverse of multiplication, that is: $$X div Y =Xcdot frac 1Y$$



                So you have: $$56cdot 100 cdot frac18 =56cdotfrac18cdot100$$
                Which is obvious.






                share|cite|improve this answer









                $endgroup$













                  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',
                  autoActivateHeartbeat: false,
                  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%2f3117260%2fhow-is-rearranging-56-x-100-%25c3%25b7-8-into-56-%25c3%25b78-x100-allowed-by-the-commutative-prope%23new-answer', 'question_page');
                  }
                  );

                  Post as a guest















                  Required, but never shown

























                  4 Answers
                  4






                  active

                  oldest

                  votes








                  4 Answers
                  4






                  active

                  oldest

                  votes









                  active

                  oldest

                  votes






                  active

                  oldest

                  votes









                  1












                  $begingroup$

                  Notice that you have always $div 8$, no matter the order of the other terms. You don't divide by a different number. It might help to think $div c$ as a multiplication with $d=1/c$. Then everything would look easier:
                  $$atimes bdiv c=atimes btimes d=atimes dtimes b=adiv ctimes b$$






                  share|cite|improve this answer









                  $endgroup$


















                    1












                    $begingroup$

                    Notice that you have always $div 8$, no matter the order of the other terms. You don't divide by a different number. It might help to think $div c$ as a multiplication with $d=1/c$. Then everything would look easier:
                    $$atimes bdiv c=atimes btimes d=atimes dtimes b=adiv ctimes b$$






                    share|cite|improve this answer









                    $endgroup$
















                      1












                      1








                      1





                      $begingroup$

                      Notice that you have always $div 8$, no matter the order of the other terms. You don't divide by a different number. It might help to think $div c$ as a multiplication with $d=1/c$. Then everything would look easier:
                      $$atimes bdiv c=atimes btimes d=atimes dtimes b=adiv ctimes b$$






                      share|cite|improve this answer









                      $endgroup$



                      Notice that you have always $div 8$, no matter the order of the other terms. You don't divide by a different number. It might help to think $div c$ as a multiplication with $d=1/c$. Then everything would look easier:
                      $$atimes bdiv c=atimes btimes d=atimes dtimes b=adiv ctimes b$$







                      share|cite|improve this answer












                      share|cite|improve this answer



                      share|cite|improve this answer










                      answered 34 mins ago









                      AndreiAndrei

                      12.1k21127




                      12.1k21127























                          2












                          $begingroup$

                          The non-zero real numbers form an abelian group under multiplication. The notation $adiv b$ is shorthand for $ab^{-1}$.



                          So $ab^{-1}ne ba^{-1}$ but $56times100 times8^{-1}=56times 8^{-1}times 100$






                          share|cite|improve this answer









                          $endgroup$


















                            2












                            $begingroup$

                            The non-zero real numbers form an abelian group under multiplication. The notation $adiv b$ is shorthand for $ab^{-1}$.



                            So $ab^{-1}ne ba^{-1}$ but $56times100 times8^{-1}=56times 8^{-1}times 100$






                            share|cite|improve this answer









                            $endgroup$
















                              2












                              2








                              2





                              $begingroup$

                              The non-zero real numbers form an abelian group under multiplication. The notation $adiv b$ is shorthand for $ab^{-1}$.



                              So $ab^{-1}ne ba^{-1}$ but $56times100 times8^{-1}=56times 8^{-1}times 100$






                              share|cite|improve this answer









                              $endgroup$



                              The non-zero real numbers form an abelian group under multiplication. The notation $adiv b$ is shorthand for $ab^{-1}$.



                              So $ab^{-1}ne ba^{-1}$ but $56times100 times8^{-1}=56times 8^{-1}times 100$







                              share|cite|improve this answer












                              share|cite|improve this answer



                              share|cite|improve this answer










                              answered 34 mins ago









                              Angela RichardsonAngela Richardson

                              5,28911733




                              5,28911733























                                  1












                                  $begingroup$

                                  Hope this makes sense.



                                  $$ atimes b ÷ c $$



                                  $$=atimesdfrac{b}{c}$$



                                  $$=atimes btimesdfrac{1}{c}$$



                                  $$=(atimesdfrac{1}{c})times b$$



                                  $$=dfrac{a}{c}times b$$



                                  $$=a÷ctimes b$$






                                  share|cite|improve this answer








                                  New contributor




                                  Aditya is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
                                  Check out our Code of Conduct.






                                  $endgroup$


















                                    1












                                    $begingroup$

                                    Hope this makes sense.



                                    $$ atimes b ÷ c $$



                                    $$=atimesdfrac{b}{c}$$



                                    $$=atimes btimesdfrac{1}{c}$$



                                    $$=(atimesdfrac{1}{c})times b$$



                                    $$=dfrac{a}{c}times b$$



                                    $$=a÷ctimes b$$






                                    share|cite|improve this answer








                                    New contributor




                                    Aditya is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
                                    Check out our Code of Conduct.






                                    $endgroup$
















                                      1












                                      1








                                      1





                                      $begingroup$

                                      Hope this makes sense.



                                      $$ atimes b ÷ c $$



                                      $$=atimesdfrac{b}{c}$$



                                      $$=atimes btimesdfrac{1}{c}$$



                                      $$=(atimesdfrac{1}{c})times b$$



                                      $$=dfrac{a}{c}times b$$



                                      $$=a÷ctimes b$$






                                      share|cite|improve this answer








                                      New contributor




                                      Aditya is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
                                      Check out our Code of Conduct.






                                      $endgroup$



                                      Hope this makes sense.



                                      $$ atimes b ÷ c $$



                                      $$=atimesdfrac{b}{c}$$



                                      $$=atimes btimesdfrac{1}{c}$$



                                      $$=(atimesdfrac{1}{c})times b$$



                                      $$=dfrac{a}{c}times b$$



                                      $$=a÷ctimes b$$







                                      share|cite|improve this answer








                                      New contributor




                                      Aditya is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
                                      Check out our Code of Conduct.









                                      share|cite|improve this answer



                                      share|cite|improve this answer






                                      New contributor




                                      Aditya is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
                                      Check out our Code of Conduct.









                                      answered 29 mins ago









                                      AdityaAditya

                                      112




                                      112




                                      New contributor




                                      Aditya is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
                                      Check out our Code of Conduct.





                                      New contributor





                                      Aditya is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
                                      Check out our Code of Conduct.






                                      Aditya is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
                                      Check out our Code of Conduct.























                                          1












                                          $begingroup$

                                          Because division is the inverse of multiplication, that is: $$X div Y =Xcdot frac 1Y$$



                                          So you have: $$56cdot 100 cdot frac18 =56cdotfrac18cdot100$$
                                          Which is obvious.






                                          share|cite|improve this answer









                                          $endgroup$


















                                            1












                                            $begingroup$

                                            Because division is the inverse of multiplication, that is: $$X div Y =Xcdot frac 1Y$$



                                            So you have: $$56cdot 100 cdot frac18 =56cdotfrac18cdot100$$
                                            Which is obvious.






                                            share|cite|improve this answer









                                            $endgroup$
















                                              1












                                              1








                                              1





                                              $begingroup$

                                              Because division is the inverse of multiplication, that is: $$X div Y =Xcdot frac 1Y$$



                                              So you have: $$56cdot 100 cdot frac18 =56cdotfrac18cdot100$$
                                              Which is obvious.






                                              share|cite|improve this answer









                                              $endgroup$



                                              Because division is the inverse of multiplication, that is: $$X div Y =Xcdot frac 1Y$$



                                              So you have: $$56cdot 100 cdot frac18 =56cdotfrac18cdot100$$
                                              Which is obvious.







                                              share|cite|improve this answer












                                              share|cite|improve this answer



                                              share|cite|improve this answer










                                              answered 29 mins ago









                                              Rhys HughesRhys Hughes

                                              6,7101530




                                              6,7101530






























                                                  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.




                                                  draft saved


                                                  draft discarded














                                                  StackExchange.ready(
                                                  function () {
                                                  StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fmath.stackexchange.com%2fquestions%2f3117260%2fhow-is-rearranging-56-x-100-%25c3%25b7-8-into-56-%25c3%25b78-x100-allowed-by-the-commutative-prope%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

                                                  Costa Masnaga

                                                  Fotorealismo

                                                  Sidney Franklin