How to Calculate Percentages

Step-by-Step Guide

1. 1

   Step 1: Know what a percentage is.

   A percentage is a way to express a number as a part of a whole.
   
   To calculate a percentage, we look at the whole as equal to 100%.
   
   For example, say you have 10 apples (=100%).
   
   If you eat 2 apples, then you have eaten 2/10 × 100% = 20% of your apples and you are left with 80% of your original apples.
   
   The term "percent" in English comes from the Italian per cento or the French pour cent, which literally mean per hundred. , For instance, let's say we have a jar containing 1199 red marbles and 485 blue marbles, making it 1684 marbles in total.
   
   In this case, 1684 makes up a whole jar of marbles, and will be set equal to 100%. , Let's say we want to find out the percentage of the jar that is taken up by the 485 blue marbles. , In our example, we need to find out what percent 485 (number of blue marbles) is of 1684 (total number of marbles).
   
   Therefore the fraction in this case is 485/1684. , To turn 485/1684 into a decimal, divide 485 by
   1684.
   
   This comes to
   0.288. , Multiply the result obtained in the step above by
   100.
   
   For this example,
   0.288 multiplied by 100 equals
   28.8 or
   28.8%.
   
   A simple way to multiple a decimal by 100 is to move the decimal to the right two places.
2. 2

   Step 2: Determine the value of the whole.

3. 3

   Step 3: Find the value that you want to turn into a percentage.

4. 4

   Step 4: Put the two values into a fraction.

5. 5

   Step 5: Convert the fraction into a decimal.

6. 6

   Step 6: Convert the decimal into a percent.

Detailed Guide

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