Percentages are all around us -- from 3.4% monthly percentages to 80% laundry. It's helpful to know about percentages, what they mean, and how to calculate them. To calculate it is not as difficult as you think, and the way to calculate it is shown below.
Step
Method 1 of 3: Calculating Overall Percentage
Step 1. Know what percentages are
a percentage is a way of expressing a number as part of a whole. To calculate the percentage, we look at the whole as 100%. For example, you have 10 apples (=100%). If you eat 2 apples, then you have eaten 2/10 x 100% = 20% of your apples and what remains is 80% of your total apples.
The term "perfect" in English comes from the Italian "per cento" or the French "pour cent", which means "every hundred"
Step 2. Determine the overall value
Let's say we have a jar containing 1199 red marbles and 485 blue marbles, bringing the total to 1684. In this case, 1684 is the total marble in the jar and equals 100%.
Step 3. Find the value you want to convert into a percentage
Let's say we want to know the percentage of the jar filled with 485 blue marbles.
Step 4. Put both values in fraction form
In our example, we need to know what percentage is 485 (number of blue marbles) of 1684 (total of marbles). Thus, the fraction for this case is 485/1684.
Step 5. Convert the fraction to decimal form
To convert 485/1684 to decimal form, divide 485 by 1684 to make 0.288.
Step 6. Convert decimal form to percent form
Multiply the result obtained using the steps above by 100. For this example, 0, 288 multiplied by 100 equals 28, 8 or 28, 8%.
A simple way to multiply a decimal by 100 is to move the decimal to right two places.
Method 2 of 3: Converting Percentages
Step 1. Why change the form of a percentage?
Sometimes you are given a percentage of something and need to know the percent value. For example, calculating taxes, tips, and loan interest.
Step 2. Know the initial value
Suppose you borrow money from a friend who is about to pay interest. The initial amount you borrow is $15 and the interest rate is 3% daily. These are the two numbers you will need to do the calculations.
Step 3. Convert percent to decimal
Multiply percent by 0.01 or by moving the decimal to left two places. This changes 3% to 0.03.
Step 4. Multiply the original number by the new decimal
In this case, multiply 15 by 0.03 to get 0.45. In this example, $0.45 is the amount of interest charged each day if you don't pay your friend.
Method 3 of 3: Calculating Discount
Step 1. Know the price and discount value
This is an easy way to calculate the discounted price, but you have to make sure the percentage is accurate. Check again how much discount is given for the item you want to buy.
Step 2. Find the reciprocal of the discount percentage
The reciprocal of the percentage is 100% minus the percentage you calculated. If you want to buy clothes with a 30% discount, the opposite is 70%.
Step 3. Convert the inverted percentage to a decimal
To convert a percentage to a decimal, multiply by 0.01 or move the decimal two places to left. In this example, 70% becomes 0.7.
Step 4. Multiply the price by the new decimal
If the shirt you want is $20, multiply 20 by 0.7 to get 14. This means that the shirt is discounted to $14.
