## PCSR REVIEW SERIES WEEK 7: Conversion of Decimals, Percent, and Fractions Operations

After learning about solving quations, let’s learn about operations on decimals. Let’s also learn the conversion among decimals, fractions, and percent. Below are the articles and videos about these topics. Exercises and problems will be posted later.

ARTICLES

Operations on Decimals

Conversion

Conversion

Enjoy!

## Practice Quiz on Converting Fraction to Percent

After learning converting fraction to percent, let’s practice by answering the following questions. There are different methods in converting fraction to percent. One method is to convert the fraction to decimal first, then multiply by the result by 100. However, in the solutions below, we will mostly use equivalent fractions. That is, since we want a% means a/100, we will convert the fraction to its equivalent fraction with denominator 100. We can do this by multiplying the numerator and the denominator  by the same number.

Practice Quiz: Converting Fraction to Percent

1.) 3/4

2.) 5/8

3) 9/10

4.) 1/4

5.) 7/10

6.) 3/5

7.) 3/8

8.) 7/20

9.) 1/5

10.) 7/50

1). We can make 3/4 as 100 by multiplying the denominator by 25. In effect,

$\displaystyle \frac{3}{4} = \frac{3 \times 25}{4 \times 25} = \frac{75}{100}$.

Therefore, 3/4 is equal to 75%.

2.) What number should we multiply to 8 to get 100? That is, 100/8 or 12.5.

$\displaystyle \frac{5}{8} = \frac{5 \times 12.5}{8 \times 12.5} = \frac{62.5}{100}$.

Therefore, 5/8 is equal to 62.5%.

3.) This is a bit easy. What will you multiply to 10 to get 100? Of course, it’s 10.  So,

$\displaystyle \frac{9}{10} = \frac{9 \times 10}{10 \times 10} = \frac{90}{100}$.

Therefore, 9/10 is equal to 90%.

4.) What should you multiply by 4 to get 100? It’s 25.

$\displaystyle \frac{1}{4} = \frac{1 \times 25}{4 \times 25} = \frac{25}{100}$

So, 1/4 is equal to 25%.

5.) To make the denominator 100, we should multiply by 10 (similar to number 3). So,

$\displaystyle \frac{7}{10} = \frac{7 \times 10}{10 \times 10} = \frac{70}{100}$.

So, 7/10 is equal to 70%.

6.) What should we multiply by 5 to get 100? It’s 20. So,

$\displaystyle \frac{3}{5} = \frac{3 \times 20}{5 \times 20} = \frac{60}{100}$

So, 3/5 is equal to 60%.

7.) As discussed in number 2, we should multiply 8 by 12.5 in order to get 100. Therefore,

$\displaystyle \frac{3}{8} = \frac{3 \times 12.5}{8 \times 12.5} = \frac{37.5}{100}$.

So, 3/8 is equal to 37.5%.

8.) What should be multiplied by 20 to get 100? It’s 5. So,

$\displaystyle \frac{7}{20} = \frac{7 \times 5}{20 \times 5} = \frac{35}{100}$.

So, 7/20 is equal to 35%.

9.) What should be multiplied by 5 to get 100? It’s 20. So,

$\displaystyle \frac{1}{5} = \frac{1 \times 20}{5 \times 20} = \frac{20}{100}$

Therefore, 1/5 is equal to 20%.

10. What should be multiplied by 50 to get 100? It’s 2. So,

$\displaystyle \frac{7}{50} = \frac{7 \times 2}{50 \times 2} = \frac{14}{100}$.

So, 7/50 is equal to 14%.

## The Fraction-Decimal-Percent Conversion Series

If you are having a hard time converting fractions to decimals and vice versa, converting fraction to percent and vice versa, and converting decimal to percent and vice versa, you can read the posts below. I will be creating practice tests with complete solutions later, so stay posted.

Enjoy learning and good luck for the May 3 exam.

## How to Convert Fraction to Percent Part 2

In the Part 1, we have learned how to convert fraction to percent by relating the denominator to 100 by multiplication or division. In this post, we do its ‘algebraic version.’ This method is a generalized method to the previous post especially for numbers that do not divide 100 or cannot be divided by 100 easily. However, to see the relationship between the two methods, let us do the first example in Part 1 of this series.

Example 1: What is the equivalent of 1/5 in percent.

Recall that in Part 1, we multiplied both the numerator and the denominator by 20, to make the denominator 100. That is,  Continue Reading

## How to Convert Fraction to Percent Part 1

In the previous post, we have learned how to convert percent to fraction. In these series of posts, we learn the opposite: how to convert fraction to percent. I am going to teach you three methods, the last one would be used if you forgot the other two methods, or if the first two methods would not work. Please be reminded though to understand the concept (please do not just memorize).

The first method can be used for fractions whose denominators can be easily related to 100 by multiplication or division. Recall that from Converting Percent to Fraction, I have mentioned that when we say percent it means “per hundred.” In effect, n% can be represented by n/100. Therefore, if you have a fraction and you can turn it into n/100 (by multiplication/division), then you have turned it into percent. Continue Reading