Calculating 20% of 35 – Quick Math Guide!

Welcome to our quick math guide on calculating 20% of 35! If you’ve ever wondered what the result is when you find 20% of 35, you’ve come to the right place. Whether you need to solve this for a math problem, a business calculation, or just out of curiosity, we’ll provide you with a simple and straightforward formula to help you find the answer.

To calculate 20% of 35, you can use the following formula: multiply 35 by 0.20. The result is 7. So, 20% of 35 is equal to 7. It’s as simple as that!

Now that you know the formula, let’s dive deeper into the concept of percentages and how they can be applied in various scenarios.

Key Takeaways:

  • Calculating 20% of 35 is done by multiplying 35 by 0.20, resulting in 7.
  • Percentages are used to express a proportion or fraction of a whole number out of 100.
  • Understanding percentages is essential for practical applications such as discounts, interest rates, and grades.
  • Mental math tricks can help you quickly find percentages without a calculator.
  • Regular practice and review improve calculation speed and accuracy.

Understanding Percentages

Percentages play a crucial role in various aspects of our lives, from financial calculations to understanding statistics. But what exactly are percentages, and how do we calculate them?

Percentages are used to express a proportion or fraction of a whole number out of 100. They provide a standardized way to compare values and understand relative quantities.

When we see the symbol “%,” we know that it represents a percentage. For example, 20% means 20 out of 100.

To better comprehend percentages, it’s helpful to know that they can be expressed as fractions and decimals. For instance, 20% is equivalent to the fraction 20/100 or the decimal 0.20.

Converting percentages into fractions can be done by taking the percentage value as the numerator and 100 as the denominator. Similarly, transforming percentages into decimals involves dividing the percentage value by 100.

Example: To convert 35% into a fraction, we write it as 35/100. To convert 35% into a decimal, we calculate 35 ÷ 100 = 0.35.

Understanding percentages is vital for a variety of calculations and applications. Whether you’re managing your finances, analyzing data, or interpreting statistics, percentages provide valuable insights and help make informed decisions.

Applying Percentages in Algebra Problems

Percentages play a crucial role in solving algebraic problems, offering a versatile tool for calculating grades, discounts, interest rates, and various other scenarios. In algebra, percentages are typically represented as decimals to simplify calculations. For example, 80% is written as 0.80. By utilizing percentages, we can solve equations and determine unknown variables, enabling a deeper understanding of algebraic concepts.

When working with percentages in algebra, it’s important to remember that they express a portion or fraction of a whole number out of 100, making them applicable to a wide range of algebraic scenarios. By using percentages, we can quantify proportional relationships and analyze numerical data effectively.

Let’s take a closer look at a few applications of percentages in algebra:

Calculating Grades

Percentages are commonly used to determine grades in academic settings. The total marks achieved by a student in an exam are often converted into a percentage to evaluate their performance. For instance, if a student scores 80 marks out of 100, their grade can be calculated by finding the percentage represented by 80 out of 100. By using algebraic percentage calculations, educators can accurately assess students’ achievements and track their progress throughout the academic year.

Discounts and Markups

Percentage calculations are instrumental in determining discounts and markups in commercial settings. Businesses often offer discounts on products or services to attract customers. By applying percentages, the discounted price can be easily calculated. Similarly, markups, which represent the increase in price for goods or services, can also be determined using percentages.

Interest Rates

Interest rates involve the application of percentages in algebraic problems. Whether it’s calculating the interest on a loan or the growth of an investment, percentages are used to express the rate and determine the final amount. Algebraic percentage calculations enable financial institutions and individuals to make informed decisions about borrowing, lending, and investment opportunities.

By incorporating percentages into algebra, we unlock a versatile tool that empowers us to solve a wide range of real-world problems. The ability to apply percentages in algebraic equations enhances our numerical fluency and critical thinking skills, enabling us to navigate complex mathematical challenges with confidence.

applying percentages in algebra

Mental Math Tricks for Finding Percentages

When it comes to calculating percentages quickly and accurately, mental math tricks can be incredibly handy. These techniques allow you to perform percentage calculations in your head, without the need for a calculator or pen and paper. Whether you’re solving a quick math problem or making estimates on the go, these tricks can save you time and effort.

One useful trick is to calculate 10% of a number by simply dividing it by 10. For example, if you need to find 10% of 80, divide 80 by 10 to get 8. This method works because 10% is equivalent to one-tenth of a whole.

Another trick is to find 20% of a number by first determining 10% and then doubling it. For instance, if you want to calculate 20% of 50, start by finding 10% of 50, which is 5. Then, double this value to get 20%, which is 10.

To quickly find 50% of a number, divide it by 2. For instance, if you need to determine 50% of 64, divide 64 by 2 to get 32. This trick works because 50% is half of the whole.

These mental math tricks are particularly useful for making rough estimates and performing quick calculations. Although they may not provide the exact answer, they can help you get close to the correct result without spending too much time.

By mastering these mental math tricks, you can become more confident and efficient in calculating percentages in your head. Practice using these tricks in various scenarios to strengthen your mental math skills and improve your ability to perform quick percentage calculations on the go.

“Mental math tricks can be real lifesavers when you need to quickly estimate percentages. With a little practice, you’ll be able to impress your friends and make accurate calculations in your head.”

Comparison of Mental Math Tricks for Finding Percentages

Percentage Mental Math Trick
10% Divide the number by 10
20% Find 10% and double it
50% Divide the number by 2

These mental math tricks for percentages can be incredibly useful when you need to quickly estimate or calculate percentages in your head. With practice, you’ll become more skilled at mental math and be able to perform quick percentage calculations with ease.

mental math tricks for percentages

Finding 20% of 35 Using Mental Math

To calculate 20% of 35 mentally, you can utilize a simple mental math method that avoids the need for a calculator. Start by finding 10% of 35, which is 3.5. You can easily determine this by moving the decimal point one place to the left.

Example Calculation:

10% of 35 = 3.5

Once you have the value of 10%, you can double it to find 20%. By doubling 3.5, you get 7. Therefore, the result of finding 20% of 35 mentally is 7.

This mental math technique provides a quick and efficient way to calculate percentages without relying on a calculator. It is particularly useful in situations where a rough estimate is sufficient or when performing calculations mentally is more convenient. By practicing and familiarizing yourself with these mental math strategies, you can enhance your calculation skills and perform quick percentage calculations with ease.

Finding 20% of 35 using mental math

Percentage Change Calculation

To calculate the percentage change, you need to find the difference between two values and express it as a percentage of the original value. This calculation can be used to determine both percent increase and percent decrease in various scenarios. Let’s explore how it works:

Suppose you have a value that increases from 35 to 40. To find the percentage increase, you need to subtract the original value from the new value (40 – 35 = 5). Next, divide this difference by the original value (5 ÷ 35 ≈ 0.14). Lastly, multiply the result by 100% to express it as a percentage (0.14 × 100% = 14%). So, the percentage increase from 35 to 40 is approximately 14%.

Similarly, if you have a value that decreases from 40 to 35, you can calculate the percentage decrease using the same formula. Start by finding the difference between the original value and the new value (40 – 35 = -5). Then, divide this difference by the original value (-5 ÷ 40 ≈ -0.125). Finally, multiply the result by 100% to express it as a percentage (-0.125 × 100% = -12.5%). Therefore, the percentage decrease from 40 to 35 is approximately 12.5%.

Here’s a summary of the formula:

Change = New Value – Original Value
Percentage Change = (Change / Original Value) × 100%

By using this formula, you can easily calculate the percentage change, whether it’s an increase or decrease, in various contexts such as financial analysis, sales performance, or statistical data.

Pictorial Representation of Percentage Change:

Let’s take a closer look at the percentage change calculation with the help of a visual representation. The following table illustrates the percentage change for different scenarios:

Original Value New Value Change Percentage Change
35 40 5 14%
40 35 -5 -12.5%

calculating percentage change

In the first row, the original value is 35, and it increases to 40. The change is 5, representing a 14% increase. In the second row, the original value is 40, and it decreases to 35. The change is -5, representing a 12.5% decrease.

By visually analyzing the percentage change, you can gain a clearer understanding of the magnitude and direction of the change. This aids in interpreting data, identifying trends, and making informed decisions based on the percentage change.

Remember that percentage change calculations are versatile and can be applied across different scenarios, from analyzing financial investments to tracking population growth. It’s a valuable tool for evaluating trends, comparing data sets, and gaining insights into the relative performance or impact of certain values.

Percentages and Proportions

Percentages and proportions are closely connected. They both involve the comparison of quantities and their relative sizes. When two ratios have the same proportion, they can be expressed as different percentages.

For example, consider the ratio 1/2. This can be written as 50/100 or as 50%. Although the proportions are the same, the percentages are different. This demonstrates how different percentages can represent the same proportion.

Proportional relationships can be effectively represented as percentages. This allows for easy comparison between different quantities. By converting proportions to percentages, we can gain insights into the relationships between variables in a clear and concise manner.

Equivalent Percentages

Proportions are not limited to specific percentages. For any proportion, there are multiple equivalent percentages that can represent it.

For example, let’s consider the proportion 3/4. The corresponding percentages for this proportion can be calculated as follows:

Proportion Percentage Equivalent
3/4 75%
6/8 75%
12/16 75%

In the table above, we can see that different proportions of 3/4, such as 6/8 and 12/16, all have the same percentage equivalent of 75%. This demonstrates the flexibility of percentages and their ability to represent various proportions.

Proportional Relationships

Proportions and percentages play a crucial role in understanding and analyzing proportional relationships. Through percentages, we can compare quantities and gain insights into their relative sizes.

Let’s consider a scenario where the price of a product is reduced by 20%. This decrease in price represents a proportional relationship. By expressing this decrease as a percentage, we can easily compare it to other proportional changes.

“The new price is 80% of the original price.”

The quote above shows how we can express the decrease in price as a proportion, 80%, which represents the new price in relation to the original price. This proportional relationship allows for effective comparison and analysis.

By understanding percentages and proportions, we can interpret data, identify trends, and make informed decisions based on relative values. They provide valuable tools for analyzing numerical relationships and drawing meaningful conclusions.

Real-Life Applications of Percentage Calculations

Percentage calculations are not just limited to mathematical exercises; they have practical applications in everyday life. Understanding how to use percentages can help you make informed decisions and manage your finances effectively. Let’s explore some real-life scenarios where percentages are commonly used:

Sales and Discounts

Whether you’re shopping online or at a retail store, discounts are everywhere. Understanding percentages allows you to calculate the final price after applying a discount. For example, if an item is on sale for 30% off its original price of $50, you can calculate the discounted price as:

$50 – (30% * $50) = $35

Using percentages, you can easily determine the savings and make informed purchasing decisions.

Interest Rates

When obtaining a loan or investing in savings accounts, understanding interest rates is crucial. Financial institutions often express interest rates as percentages. For instance, if you have a savings account with an annual interest rate of 3%, you can calculate the interest earned over a specific period by multiplying the principal amount by the interest rate:

Interest = Principal * Interest Rate

Knowing how to calculate interest rates empowers you to make informed financial decisions.

Grading Systems

Percentage calculations play a vital role in educational settings. Grading systems often use percentages to evaluate student performance. For example, if a test is scored out of 100 and a student receives 85 marks, the percentage can be calculated as:

(85 / 100) * 100% = 85%

Percentages provide an accurate representation of a student’s performance and enable educators to assess progress effectively.


Understanding percentages is essential for calculating taxes accurately. Sales tax, income tax, and property tax are generally based on a percentage of the total value or amount. By calculating percentages correctly, you can determine the amount owed and ensure compliance with tax regulations.

Real-Life Application Percentage Calculation
Sales and Discounts Original Price – (Discount Percentage * Original Price)
Interest Rates Principal * Interest Rate
Grading Systems (Obtained Marks / Total Marks) * 100%
Taxes Total Value * Tax Percentage

These are just a few examples of how percentage calculations are applied in real-life situations. From determining savings on a sale to calculating interest earned, percentages are an essential tool for making informed decisions and managing various aspects of daily life. Developing a strong understanding of percentages can empower you to navigate these scenarios with confidence and make accurate calculations on the go.

real-life applications of percentages

Additional Percentage Calculation Techniques

In addition to the mental math tricks mentioned earlier, there are alternative methods and techniques for calculating percentages, providing you with more flexibility and options. These techniques can be particularly useful when dealing with complex calculations or when precise accuracy is required.

Using Proportions

One method for calculating percentages is by using proportions. A proportion is an equation that states that two ratios are equal. By setting up a proportion and solving for the variable, you can find the desired percentage easily.


A product is on sale for 20% off. The original price was $100. What is the sale price after the discount?

To find the sale price, you can set up the proportion: x/100 = 80/100

By solving for x, you can find that the sale price is $80.


An alternative method for finding percentages is through cross-multiplication. This technique involves multiplying the values on a diagonal and setting them equal to each other. By solving the resulting equation, you can determine the percentage.


You want to calculate the percentage increase between two values, $50 and $70. What is the percentage increase?

Using cross-multiplication, the equation becomes: 50 * x = 70 * 100

Solving for x, you can find that the percentage increase is 40%.

Converting Between Fractions and Decimals

Converting percentages to fractions and decimals, and vice versa, can also be a helpful technique in percentage calculations. This method allows you to work with different representations of percentages, depending on the calculation requirements.


You want to find 25% of 80. Instead of calculating 25% directly, you can convert it to a decimal by dividing it by 100. So, 25% becomes 0.25.

Next, you can multiply the decimal (0.25) by 80 to find the result: 0.25 * 80 = 20.

Therefore, 25% of 80 is equal to 20.

By applying these additional percentage calculation techniques, you can expand your repertoire of methods for finding percentages. Depending on the situation and your preferences, you can choose the most suitable technique to achieve accurate and efficient calculations.

Method Description
Using Proportions Set up a proportion equation and solve for the variable to find the percentage.
Cross-Multiplication Multiply values on a diagonal and set them equal to each other, then solve the equation for the percentage.
Converting Between Fractions and Decimals Convert percentages to fractions or decimals, and vice versa, to work with different representations.

Reviewing Mental Math and Percentage Calculations

Mastering mental math and percentage calculations requires practice, understanding of concepts, and familiarity with their applications in various scenarios. Regular review and practice can enhance calculation speed and accuracy, ultimately leading to improved problem-solving abilities when dealing with percentages.

It is crucial to have a solid grasp of the fundamental concepts of percentages and proportions. Percentages represent fractions or proportions out of 100 and are commonly denoted by the symbol “%”. They play a significant role in many real-life situations, such as calculating discounts, interest rates, and even analyzing data.

By practicing mental math techniques, you can develop the ability to solve percentage-related problems without relying heavily on calculators or other tools. Quick mental calculations can save time and enable you to estimate percentages on the go, making everyday calculations more efficient.

“The more you practice mental math and percentage calculations, the more confident and proficient you become.”

Practicing mental math and percentage calculations can involve various techniques and strategies. Here are a few tips to enhance your skills:

  1. Multiply by 10: To find 10% of a number, move the decimal point one place to the left. For example, 10% of 3500 is 350.
  2. Use Proportions: Proportions can be used to solve a variety of percentage problems. For instance, if 15% of a quantity is known, the corresponding amount for 30% can be easily calculated by doubling the known value.
  3. Divide by 2: Finding 50% of a number is as simple as dividing it by 2. For example, 50% of 80 is 40.

Regularly reviewing mental math and percentage calculations will solidify your understanding and improve your problem-solving abilities. It’s crucial to practice these skills in a variety of contexts and scenarios to ensure their practical application and reinforce your comprehension.

Remember, mental math and percentage calculations are valuable skills that can save time and provide quick estimates in real-life situations. With consistent practice and a solid foundation, you’ll become more confident and proficient in your ability to tackle percentage-related problems anywhere, anytime.

Keep practicing, and soon you’ll be a master of mental math and percentage calculations!

mental math review


Understanding percentages is crucial in various aspects of life, whether it’s managing finances, solving mathematical problems, or making everyday calculations. By mastering the art of percentage calculations and employing mental math techniques, you can quickly and accurately determine percentages in a wide range of scenarios. Regular practice and familiarity with these concepts will greatly enhance your confidence and proficiency when working with percentages.

In summary, percentages allow us to express fractions or proportions of a whole number out of 100. They can be represented as decimals or fractions for easier calculation. Mental math tricks, such as finding 10% and doubling it to find 20%, enable us to make quick estimations without relying on calculators. These techniques are particularly useful when you need to calculate percentages on the fly.

Understanding percentages is of utmost importance, as it enables us to apply this knowledge to real-life situations. From calculating discounts and interest rates to determining grades and taxes, percentage calculations are integral to our daily lives. By developing a solid grasp of percentages, you can make informed decisions and effectively manage your financial affairs.


What is the formula to calculate 20% of 35?

To calculate 20% of 35, you can multiply 35 by 0.20, which gives you the result of 7.

How do I find 20% of 35?

To find 20% of 35, you can multiply 35 by 0.20 or divide 35 by 5, which also gives you 7.

Can you show me how to calculate 20% of 35 in numbers?

Certainly! The calculation for finding 20% of 35 is 35 multiplied by 0.20, which equals 7.

What is 20 percent of 35?

20% of 35 is equal to 7.

How can I mentally calculate 20% of 35?

To quickly find 20% of 35 mentally, you can start by finding 10% of 35, which is 3.5. Then, double that value to get 20%, which equals 7.

How do I calculate percentage change?

Percentage change can be calculated by finding the difference between two values and expressing it as a percentage of the original value. For example, if a value increases from 35 to 40, the percentage increase is (40-35)/35 * 100% = 14.3%.

What are percentages used for?

Percentages are used to express a proportion or fraction of a whole number out of 100. They are commonly used in algebraic problems, calculating discounts, interest rates, grades, and taxes, among other practical situations.

Are there other techniques for calculating percentages?

Yes, in addition to multiplying by the decimal form, you can use proportions, cross-multiplication, or convert between fractions and decimals to calculate percentages.

Why is it important to understand percentages?

Understanding percentages is essential for making informed decisions and managing finances effectively. They have a wide range of applications in various areas of life, including finance, mathematics, and everyday calculations.

How can I improve my mental math and percentage calculations?

Regular practice and familiarity with the concepts of percentages, proportions, and their applications can enhance calculation speed and accuracy. By practicing mental math and reviewing percentage calculations, you can improve your skills.