A Brief Overview of Methods for Solutions to Simple Percent Problems

Percent Problems can be arranged in two types Vertical  or Horizontal

An elementary method is Proportions an advanced method is an Algebra Equation.

The Law of Proportions applies to both types of arrangements for Proportions.

 

The Elementary method or arrangement changes the % to a fraction

while changing the (of N) and (is N) to a fraction.

 

The use of Calculators if highly encouraged for students of all ages.

Solutions to Percent Problems using Proportions

 

25% of N is 4          50% of 28 is N        N% of 24 is 18        125% of 20 is N

 

25      4                 50      N                N       18               125     N

----  =  ----              ----  =  ----              ----  =  ----              ----  =  ----

100     N                100     28               100     24               100     20

 

25N = 400              1400 = 100N           24N = 1800             2500 = 100N

 

N = 16                   14 = N                   N = 75                   25 = N

 

Checking

25% of 16 is 4         50% of 28 is 14        75% of 24 is 18        125% of 20 is 25

 

 

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The Algebraic method or arrangement changes the (of to X) while the (is to =)

while the other elements to the statements become parts of an equation.

 

The use of Calculators if highly encouraged for students of all ages.

Solutions to Percent Problems using Algebraic Equations

 

25% of N is 4          50% of 28 is N        N% of 24 is 18        125% of 20 is N

 

.25 *  N = 4             .50 * 28 = N            N * 24 = 18             .125 * 20 = N

 

N = 16                   14 = N                   N = .75                  25 = N

 

Checking

25% of 16 is 4         50% of 28 is 14        75% of 24 is 18        125% of 20 is 25

 

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Tom Love                   Malone College                  Fall 2003

 

Reference: Basic College Mathematics by K Elayn Martin-Gay