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4-2                     Percentages, Ratios and Relationships                         CH 4]




                             selling price when sold. As percent means hundredth, 8% means 8 hundredths, which is 0.08
                             in decimal form.
          % : In mathematics,   A percentage (%) symbol is a dimensionless number (pure number) though the value it is
          a percentage is a   attached to indicates that the value is in hundredths.
          number or ratio       The percent (%) affects decimal placement for a number and expresses a relationship of
          expressed as a     the number to another number as a value of the whole, indicated in the opening paragraphs.
          fraction of 100. It is   Once the relationship is established the % symbol is concatenated to the calculated value.
          often denoted using
          the percent sign,   THE VALUE and POWER OF ONE and PERCENT (%)
          "%", or the
          abbreviations "pct.",   To appreciate the relationship of one number to another as a percentage with the symbol
          "pct"; sometimes the  % attached requires an understanding of the value of 1; And we are looking at the number as
          abbreviation "pc" is   if it were a fraction.
          also used. A          Recall the lesson on reciprocals in Chapter 2 that all numbers have a denominator and
          percentage is a    that denominator when not stated is 1; The value of one. Given the value of 300, it contains
          dimensionless      an implied denominator of 1. Given Hallie, the implied denominator is 1. Given the value of W
          number (pure       the implied denominator is 1.
          number).              Concurrent with that idea is that when any number is divided by itself it has a value of 1.
                             Such that 425 divided by 425 equals 1 (425  ÷  425 = 1 or as a fraction 425/425 = 1).
                             Similarly 12 divided by 12 equals 1 (12 ÷ 12 = 1 or 12/12 = 1). Again, this value 1 occurs
                             again when Kellen divided by Kellen equals one (Kellen ÷ Kellen= 1 or Kellen / Kellen = 1).
                                Let’s summarize this concept; any value divided by itself equals 1.

                                           425              Kellen              12
                                                =  1                =  1              =  1
                                           425              Kellen              12

                                In your thinking try this relationship: percent divided by percent? It too equals 1. The
                             arithmetic just explained validates this concept in that percent divided by percent equals 1
                             ( percent ÷ percent = 1, or percent / percent =1) and expressed as the symbol % we note the
                             same; % divided by % equals 1 or % ÷ % = 1 and % / % = 1:

                                           %
                                                =  1
                                           %

                                again, any value divided by itself equals 1.

                                In arithmetic the antonym of division is multiplication, thus we can say that when any
                             number is multiplied by the value of one the resulting answer is equal to that number.  The
                             number 435 when multiplied by 1 equals 435. Similarly, when 1 is multiplied by 212 the
                             result is 212. And when Declan is multiplied by 1 the result is Declan, or when one is
                             multiplied by Hallie the result is Hallie.

                                    435 x 1 = 435
                                                  1 x 212 = 212
                                                                 Declan x 1 = Declan
                                                                               1  x Hallie = Hallie
                                To restate the observation, when any number is multiplied by the value of 1 the resulting
                             answer is equal to that number.

                                As stated earlier, when a % is divided by a % the value of that division is 1 (%/% = 1).
                             However, a unique thing happens when a percent value (%) is divided or multiplied to any
                             number it merely adds (concatenates) the percent (%) to the value. Such that 10 times 50%
                             becomes 500% (10 x 50% = 500%); and 500% ÷ 100% = 5.

                                         50  %                             5
                                       x  10          and        100% ) 500%
                                        500 %

                                Similarly when a percent (%) number is divided by a whole number the resulting answer
                             is a percent (%), such as 100% / 80 = 1.25%; or when 30 is multiplied by 30 % the answer is
                             900%; and 900% ÷ 100% = 9.

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