How to Calculate Percentage Change: A Step-by-Step Guide

I. Introduction

Calculating percentage change is an essential skill in many areas of life, from analyzing financial data to tracking changes in measurements or population numbers. In this article, we will explore different approaches to calculating percentage change so that readers can choose the method that best suits their needs. We will cover step-by-step guides, formula-based approaches, graphic representations, real-world examples, video tutorials, and interactive quizzes.

II. Step-by-Step Guide

The step-by-step guide approach to calculating percentage change involves breaking down the calculation into simple steps that can be easily followed. To calculate percentage change using this method, follow these steps:

1. Subtract the old value from the new value.
2. Divide the result by the old value.
3. Multiply the answer by 100 to get the percentage change.

For example, suppose an investment worth $1000 increased in value to $1250. The percentage change can be calculated as follows:

1. New value – old value = $1250 – $1000 = $250
2. $250 divided by $1000 = 0.25
3. 0.25 multiplied by 100 = 25% increase

It’s important to note that when calculating a decrease, the subtraction should be the reverse order, that is, subtract the new value from the old value. Also, rounding during division, in this case, is very important to ensure accuracy. Rounding too soon can result in a significant error. Rounding too late can lead to insignificant errors that can still cause confusion.

III. Formula-Based Approach

The formula-based approach to calculating percentage change involves using a formula to calculate the change. The formula is as follows:

[(New Value – Old Value) / Old Value] x 100%

For example, if the revenue in a company increased from $1,000 to $1,200 over a period, the percentage increase can be calculated as:

• [(1200 – 1000) / 1000] x 100% = 20%

This formula might look complex, but is straightforward – the numerator represents the difference between new and old values, divided by the old value. Then, multiply it by 100 to obtain the percentage change. It is important to ensure consistency when rounding-off significant figures to a specified decimal place.

IV. Graphic Representation

Graphic representation is a helpful way to visualize percentage change. Different types of charts and diagrams can help make complex changes easier to understand. One common chart type used for illustration is line graphs, especially when one is dealing with values plotted for an extended period. Follow the following steps:

1. Select the values you want to plot
2. Using a ruler and a pencil, draw a straight line across the graph paper. Assign variable(s) to the horizontal (x) axis and vertical (y) axis.
3. Plot each coordinate point with a dot using a different color from other plotted coordinates
4. After plotting all points, connect the dots to make a line. The lines may be connected purely for aesthetics or to make a trend visible.

For instance, after investing in stocks and monitoring them over time, one can plot the percentage change on a line graph. Each point would represent the percentage change per period, connected by a line. Line graphs are adept at showing trends upward, and potential risk factors could be taken into account and fixed.

V. Real-World Examples

Real-world examples illustrate how percentage changes apply in practice. Examples may be from financial management, medicine, or physical science. For example, suppose a company’s profit in the year 2018 was $100,000 and profits increased to $130,000 in 2021. We can calculate the percentage change in the company’s profits between both years:

• [(New Value – Old Value) / Old Value] x 100%
• [(130,000 – 100,000) / 100,000] x 100%
• = 30%

Real-world examples show the application of different methods to different situations for better comprehension.

VI. Video Tutorial

A video tutorial can be an excellent way for visual learners to understand how to calculate percentage change. Such videos use audio, video, and graphics, which can help break down complex calculations into smaller, more understandable parts. A video’s strength is that it shows the process step-by-step and accounts for every rounding step involved.

When selecting a video tutorial, it’s essential to ensure it’s clear, concise, and easy to understand. Pick a video tutorial with high-quality video and sound. Before using the video to make decisions, test the information on real examples to ensure accuracy.

VII. Interactive Quizzes

Interactive quizzes are an excellent way to test the knowledge acquired in the article. Also, interactive quizzes provide an opportunity for readers to learn how to evaluate solutions quickly and correctly. Typical examples of questions that can be used in an interactive quiz include:

• What is the percentage increase of 10 to 12?
• Calculate the percentage decrease when 70 is subtracted from 100?
• What is the percentage increase between the years 2020 and 2021 when the profit increased from $200,000 to $400,000?

These questions remind us of different approaches to calculating percentage changes while testing comprehension and understandingness.

VIII. Conclusion

This article has explored different approaches to calculating percentage change. Our step-by-step guide outlines a simple and more straightforward approach. Our formula-based approach shows an intuitive method of calculating complex change. We also introduced the benefits of using graphic representations and real-world examples to understand percentage change. Additionally, we provided helpful links to video tutorials and interactive quizzes to supplement learning of different approaches. By experimenting with different methods, readers can obtain the best result for their unique situation.