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Percents can be seen in numerous daily situations all over the world because they are an easy way to express and relate data. This lesson will focus on converting different forms of numbers into percents and vice versa. The lesson will also show how percents appear in everyday life.

Catch-Up and Review

Here are a few recommended readings before getting started with this lesson.

Challenge

Phone's Battery Level

A sudden loud sound coming from Paulina's phone wakes her up. It iss and time to start getting ready for school. When she looks at her phone, Paulina realizes that she forgot to charge it the night before. The battery is at only
A phone with 14 percent battery level
External credits: @jannoon028
She connects her phone to a charger and starts getting ready.
a What fraction in its simplest form expresses the current battery level?
b Paulina disconnects her phone as soon as she is ready to go to school. The battery is charged up to of its capacity. What percent does Paulina see on the screen?
Discussion

Percents

A percent is the ratio of a number to Percents are usually denoted by the symbol

For example, five percent, or is the ratio of to
Percentages are often used in real-life situations. For example, saline is a mixture of salt and water often used to help with dry eyes or to clean and store contact lenses, as it does not irritate the eyes. Saline contains salt. This means that every grams of saline contains grams of salt.
Another situation in which percentages can be used is sales. For example, if a jacket is on sale, a store may advertise that it is off. Then, the price has been lowered by If the jacket originally cost then the price was lowered by
Discussion

Converting Fractions Into Percents

It is possible to convert a fraction into a percent and vice versa. Consider the following fraction.
This fraction can be rewritten as a percent by following two steps.
1
Divide the Numerator by the Denominator
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First, divide the numerator by the denominator. In this case, the numerator is and the denominator is The procedure of long division can be used to divide up to four decimal places.
The long division of 14 over 87
The quotient is This is the decimal equivalent of the fraction.
2
Multiply by
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Next, multiply the result by to convert it to percent. Note that multiplying a decimal number by comes down to moving the decimal point two places to the right.
0.1609 becomes 16.09 after multiplying by 100
The result is which can be rounded to Finally, add a percent sign after the number.
Therefore, the fraction represents about
Note that the order of these two steps can be reversed. In other words, the fraction can be multiplied by first, before calculating the quotient of the numerator by the denominator.

Extra

Converting Different Fractions
Input a fraction whose numerator and denominator are less than Then, click Submit and Convert to see how it can be converted into a percent. In this applet, the fraction will be multiplied by first.
The submitted fraction is converted to a percent
Example

Getting the Test Score

Paulina's first class is math. The teacher gives everyone back their graded papers from last Thursday's test. Paulina is thrilled to see that she got answers correctly.

Test sheet with a score A
There were questions in total. Paulina wonders if she managed to answer of the questions correctly. Find the fraction that describes Paulina's score and then express it as a percent.

Hint

Which number is the total and which is the part of the total? Use the definition of a percent.

Solution

It is given that Paulina answered out of questions correctly. This information will be used to first write a fraction. Since the total number of questions is this is the denominator. The number of answers Paulina got correct is which represents a part of so it is the numerator.
Now this fraction can be expressed as a percent. Start by writing it as a fraction with a denominator of Note that is a factor of
This means that multiplying the numerator and denominator by will result in an equivalent fraction with a denominator of
Recall the definition of a percent — the ratio of a number to
This means that the fraction represents
Therefore, Paulina did score more than on the math test. Great job!

Alternative Solution

Fraction represents the number of correct answers Paulina got on the test. This number can be rewritten as a percent by following two steps. First, divide the numerator by the denominator by using long division.
The long division of 23 over 25
The quotient is Next, multiply this decimal number by to write it as a percent. This can be done by moving the decimal point two places to the right.
0.92 becomes 92.0 after multiplying by 100
The product is or By adding a percent sign, it can be concluded that Paulina got of the answers correct on her math test.
Discussion

Converting Percents Into Fractions

It is possible to convert a percent into a fraction and the other way around. Consider the following percent.
This percent can be written as a fraction by following two steps.
1
Write as a Fraction Whose Denominator Is
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Since a percent is the ratio of a number to write it as a fraction whose numerator is the number part of the percent and whose denominator is
2
Simplify the Fraction
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Next, check whether the fraction can be simplified. First, split the numerator and denominator into prime factors. This process is shown below for
The numbers share two common factors. Their product is the greatest common factor (GCF) of and
Finally, divide both the numerator and denominator by
The fractions and are equivalent and they both correspond to

Extra

Converting Different Percents Between and
Input a percent that is an integer between and The process of converting this percent into a fraction will be demonstrated.
The submitted percent is converted to a fraction
Example

Choosing Between Two Lunch Options

It is lunch time! Paulina and her friends go to the school cafeteria. She is trying to decide between juice and a sandwich or tea and a croissant. What a hard decision! Her good know-it-all friend Davontay interrupts her thoughts with an interesting fact.

Image shows two students in a school cafeteria choosing between two lunch options. Option 1 (sandwich and juice) is preferred by 68% of students. Option 2 (croissant and tea) is on the right.
External credits: @pch.vector

Paulina is curious about how many students out of would choose different options, if this statistic were in fact true.

a What fraction in simplest form corresponds to the percent of students choosing Option
b How many students out of would choose Option

Hint

a Calculate what percent corresponds to the number of students choosing Option Use the definition of a percent.
b Think about what the numerator and denominator of the fraction represent.

Solution

a Davontay said that of students choose Option for lunch. Let represent all students in their school. Subtract from to find how many students choose Option
Next, this percent should be written as a fraction. Start by recalling that a percent is the ratio of a number to
Apply this formula to
This fraction should also be simplified. First, split the numerator and denominator into prime factors.
The numbers share two common factors, and Their product is the greates common factor (GCF) of and
Finally, divide the numerator and denominator by their GCF,
Therefore, corresponds to
b In Part A, it was found that students prefer Option for lunch. This fraction means that students out of would choose the tea and croissant. This leaves students who prefer Option
17 out of 25 choose Option 1 and 8 out of 25 choose Option 2
External credits: @pch.vector

After realizing this, Paulina decides to go for Option Gotta show some love to the tea and croissant! 😄

Pop Quiz

Converting Between Percents and Simplified Fractions

Convert the given percent into the corresponding simplified fraction or the other way around — the given simplified fraction into a percent. Write each percent as an integer.

A random generator that generates different percents or fractions
Discussion

Converting Mixed Numbers Into Percents

It is possible to convert a mixed number into a percent and the other way around. Consider the following mixed number.
This mixed number can be rewritten into a percent by following three steps.
1
Convert the Fraction Part to a Decimal
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The fraction part of is To rewrite it as a decimal, divide the numerator by the denominator by using long division.
The long division of 2 over 9
The quotient is approximately Note that it is often enough to divide to two decimal places.
2
Add the Decimal to the Integer Part
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The integer part of the mixed number is In the previous step, the fraction part was rewritten as the decimal number Add the integer part and the decimal part.
The mixed number can be written as the decimal number
3
Convert the Decimal to a Percent
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Rewrite the decimal as a percent by multiplying it by and adding a percent sign.
Therefore, corresponds to
Discussion

Converting Percents Into Mixed Numbers

It is possible to convert a percent into a mixed number and the other way around. Keep in mind that if a percent less than is converted into a fraction, then the result is a proper fraction. This means that it only makes sense to convert percents greater than into mixed numbers. Consider the following percent.
This percent can be rewritten into a mixed number by following three steps.
1
Write the Percent as a Fraction With as Denominator
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Recall that a percent is the ratio of a number to Start by writing the percent as a fraction whose numerator is the number part of the percent and whose denominator is
2
Divide the Numerator by the Denominator
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Divide the numerator by the denominator to rewrite the improper fraction as a mixed number. Use long division to find the quotient and remainder.
The long division of 234 over 100
The quotient is and the remainder is Write the quotient as the integer part of the mixed number and the remainder as the numerator of the fraction part. Remember that the denominator of the fraction part is the same as the denominator of the improper fraction,
3
Simplify the Fraction Part
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The final step is to simplify the fraction part. Find the gretest common factor (GCF) of the numerator and denominator by splitting and into prime factors.
The numbers share only one common factor, This means that is the GCF of and Divide the numerator and the denominator by
Finally, the mixed number that corresponds to can be written.
Example

Learning a New Dance Routine

After school, Paulina goes to her dance class. She and her partner learn a couple of new moves that keep them on their toes!
Paulina and her partner dancing
At the end of the lesson, Paulina checks her fitness tracker and discovers that she completed of her daily activity goal.
a What mixed number corresponds to this percent?
b Paulina's partner has completed of his daily activity goal. What percent corresponds to this mixed number?

Hint

a Rewrite the fraction as a mixed number by dividing the numerator by the denominator by using long division.
b Start by rewriting the fraction part as a decimal. Then, add the integer part and the decimal part together and then multiply by

Solution

a In order to rewrite as a mixed number, start by recalling the definition of a percent. A percent is the ratio of a number to
This formula can be used to rewrite as a fraction.
Next, divide the numerator by the denominator to rewrite the fraction as a mixed number. Recall that a mixed number consists of an integer part and a fraction part. Use long division to find the integer quotient and remainder.
The long division of 235 over 100
The quotient is so this is the integer part of the mixed number. The remainder is which makes it the numerator of the fraction part. The denominator of the fraction part of the mixed number is the same as the denominator of the fraction.
Finally, simplify the fraction part. Begin by splitting the numerator and denominator into prime factors.
The numbers share only one common factor, This means that this is their greatest common factor (GCF). Simplify the fraction by dividing its numerator and denominator by their GCF.
The percent of corresponds to the mixed number of
b This time the mixed number should be written as a percent. The fraction part is Divide the numerator by the denominator to write it as a decimal. Since the denominator is move the decimal point one place to the left.
7.0 after division by 10 becomes 0.7
Now, add the integer part and the decimal part This gives the decimal number
Finally, multiply the number by to rewrite it as a percent. Remember to include a percent sign!
Therefore, the mixed number is equivalent to
Pop Quiz

Converting Between Percents and Mixed Numbers

Convert the given percent into its equivalent mixed number or the given mixed number into a percent. Write the fraction part of a mixed number in simplest form. Round the percent to the nearest integer.

A random generator that generates different percents or mixed numbers
Discussion

Converting Decimal Numbers Into Percents

It is possible to convert a decimal number into a percent and vice versa. Consider the following decimal number.
This decimal can be rewritten as a percent by multiplying it by The multiplication can be done by moving the decimal point two places to the right.
5.71 becomes 571.0
Then add a percent sign.
5.71 times 100 =571%
Therefore, the decimal number is equivalent to
Example

Impressive Honey Harvest

After dance class — what a workout! — Paulina decides to stop by her granddad's house. She finds him in the garden collecting honey from his bee hives.
Bee flying over honeycombs
Paulina likes watching how hard the bees work to make this delicacy. Her grandpa proudly tells her that he has already collected times more honey than the same month last year.
a Express in percent form.
b When the year comes to an end, grandpa calculates that in total he collected times more honey this year compared to the last year. What percent does this number correspond to?

Hint

a Multiply the decimal number by and add a percent sign.
b Multiply the decimal number by and add a percent sign.

Solution

a To rewrite the decimal number as a percent, multiply the number by and add a percent sign.
1.58 times 100 =158%
The decimal number corresponds to This number implies that Paulina's grandpa collected of the amount of honey he harvested in the same month last year.
b Now the decimal number will be rewritten as a percent. To do so, multiply by and add a percent sign afterwards. An easy way to do this is by moving the decimal point two places to the right.
2.8 becomes 280.0 after multiplying by 100
Therefore, the product is or just
2.8 times 100 = 280%