Converting a fraction like 21/405 to its percentage format is a very simple and useful math skill that will help students to understand fractions and how to express them in different ways. In this article, we'll show you exactly how to convert fractions to a percentage and give you lots of examples to help you.
Looking for percentage worksheets? Click here to see all of our percentage worksheets.
There are two main ways to express a fraction as a percentage:
- Divide 100 by the numerator, and then multiply both numerator and denominator by the answer.
- Convert the fraction to a decimal first, then multiply the answer by 100.
The first step is to make sure we understand all of the terms in the problem we are trying to solve:
- Numerator - this is the number above the fraction line. For 21405, the numerator is 21.
- Denominator - this is the number below the fraction line. For 21405, the denominator is 405.
- Per cent - "per cent" means parts per hundred, so saying 50%, for example, is the same as the fraction 50100 or 510.
Convert 21/405 to Percentage by Changing Denominator
The first method we have is to convert the fraction so that the denominator is 100. Since "per cent" means parts per hundred, if we can convert the fraction to have 100 as the denominator, we then know that the top number, the numerator, is the percentage.
First, we divide 100 by the denominator:
Once we have the answer of 0.24691358024691, we can multiply both the numerator and the denominator by it to get our new "percent" fraction:
Our percent fraction is 5.1851851851852/100, which means that 21405 as a percentage is 5.19%.
Convert 21/405 to Percentage by Converting to Decimal
With this method, we first need to divide the numerator by the denominator:
Once we have the fraction in a decimal format, the answer is then multiplied by 100 to get the correct percentage:
We can see that this gives us the exact same answer as the first method: 21/405 as a percentage is 5.19%.
Both methods of converting a fraction to a percentage are pretty straightward and can be applied to any fraction easily when you have learned and memorized the steps involved.
Note, the final percentage is rounded to 2 decimal places to make the answer simple to read and understand.
Practice Percentage Worksheets
Like most math problems, percentages is something that will get much easier for you the more you practice the problems and the more you practice, the more you understand.
Whether you are a student, a parent, or a teacher, you can create your own percentage worksheets using our percentage worksheet generator. This completely free tool will let you create completely randomized, differentiated, percentafe problems to help you with your learning and understanding of percentages.
Practice Fractions to Percentage Using Examples
If you want to continue learning about how to convert fractions to percentages, take a look at the quick calculations and random calculations in the sidebar to the right of this blog post.
We have listed some of the most common fractions in the quick calculation section, and a selection of completely random fractions as well, to help you work through a number of problems.
Each article will show you, step-by-step, how to convert a fraction into a percentage and will help students to really learn and understand this process.
Calculate Another Fraction to Percentage Conversion
Enter your fraction in the boxes below and click "Calculate" to convert the fraction into a percentage.