Percentage for Beginners: A Step-by-Step Guide to Understanding Percentages
As a beginner, understanding percentages can be a daunting task. It is a fundamental concept in mathematics that is used in a range of fields, from finance to science, and it is therefore essential that we learn how to use it effectively. This guide will take you through the basics of percentages, explain how they work, and give you tips for calculating percentages effectively.

What are Percentages?

Percentages are a way of expressing proportions or fractions as a number out of 100. The word percent comes from the Latin per centum, which translates to “by the hundred”. Therefore, 100% signifies the whole amount, and everything else is expressed as a fraction of this whole. For instance, if a class has 30 students, and 15 of them are girls, the percentage of girls in the class is 50% because they are half the class.

Percentages can be used to represent multiple things, such as:

– A percentage of profits or losses
– A percentage of an amount contributed as interest
– A percentage of change in the price of an item or the value of a stock

How to Calculate Percentages

Calculating percentages is easy, and there are two basic ways to do it – by cross-multiplying or using a formula.

Cross-multiplication

Let’s take an example of a test where a student got 80 out of 100 marks. To convert this score to a percentage, cross-multiply by 100, as shown below:

80/100 x 100 = 80%

Therefore, the student scored 80% in the test.

Formula

The formula to calculate percentages is:

Amount / Full Total x 100%

Using the same example, we can calculate the percentage using the formula as:

80 / 100 x 100 = 80%

The amount in this case is the numerator (80), and the full total is the denominator (100). We multiply the resulting fraction by 100% to get the percentage.

Tips for Calculating Percentages

– Use a calculator: A calculator is an excellent tool for calculating percentages, especially if you have a lot of calculations to make.
– Convert decimals to percentages: If you have a decimal number, multiply by 100 to convert it to a percentage.
– Convert fractions to percentages: If you have a fraction, divide the numerator by the denominator, then multiply the result by 100 to convert it to a percentage.
– Round off to the nearest decimal: When calculating percentages, it is essential to round off to the nearest decimal to avoid giving out false information.

Common Percentages

There are some common percentages that you may come across, such as:

– 25%: One-quarter or one-fourth of a whole amount
– 50%: One-half or half of a whole amount
– 75%: Three-quarters or three-fourths of a whole amount
– 100%: The entire amount or whole

FAQs

Q: How do I calculate percentage change?
A: To calculate the percentage change of a value, you need to find the difference between the old value and the new value, divide it by the old value, and multiply the result by 100%.

Percentage Change = (New Value – Old Value / Old Value) x 100%

Q: How do I calculate percentage increase?
A: To calculate the percentage increase, you need to find the difference between the new value and the old value, divide it by the old value, and multiply the result by 100%.

Percentage Increase = (New Value – Old Value / Old Value) x 100%

Q: How do I calculate percentage decrease?
A: To calculate the percentage decrease, you need to find the difference between the old value and the new value, divide it by the old value, and multiply the result by 100%.

Percentage Decrease = (Old Value – New Value / Old Value) x 100%

Q: How do I calculate the percentage of a budget?
A: To calculate the percentage of a budget, divide the amount spent by the total budget, and multiply the result by 100%.

Percentage of Budget = Amount Spent / Total Budget x 100%

Conclusion

Percentages are an essential part of mathematics, and as a beginner, it is crucial to understand how they work and how to calculate them. With these tips and guidelines, you can become proficient in using percentages effectively, whether it’s for calculating interest rates, finding percentages of a whole amount, or analyzing change in values. Practice makes perfect, so keep practicing to increase your understanding of percentages.