Introduction

Percentage is a mathematical concept that permeates various areas of knowledge and daily life, such as economics, statistics, chemistry, physics, and other exact sciences. In the business and finance world, for example, percentage is widely used to express variation indices, profit percentages, interest rates, among others.

The term "percent" means "per hundred" and is represented by the symbol "%". Thus, when we say that something corresponds to a certain percentage, we are affirming that it is a fraction of one hundred. Therefore, it is essential to understand and correctly apply percentages in the development of solutions for various problems.

For the understanding of percentages, it is also important to understand concepts of fractions, proportional relationships, and basic operations. Percentage is a special case of fractions where the denominator is always 100. Thus, it relates to concepts of proportion and proportionality because it expresses a comparison between a part and a whole.

Contextualization

We live in an increasingly numerical world and percentages are everywhere. Understanding percentages helps us make better financial decisions, understand statistics and research, analyze exam results, perceive discounts in sales, among other things.

Understanding percentages is essential for interpreting data and information. In news or scientific research, for example, the presentation of percentage data is common. In college entrance exams and ENEM, percentage is also very present and integrated with various other themes.

As reliable resources for deepening and researching on the subject, we suggest:

• Khan Academy: Percentage. Khan Academy is a free educational website that offers video lessons and exercises in various subjects. In Portuguese, it offers several modules on basic percentage.
• Só Matemática: Percentage. The Brazilian website Só Matemática is quite reliable and presents the theory in a clear and objective manner, with exercises for practice.
• YouTube: Percentage with Matemático Vidigal. The channel offers Math lessons and, in particular, this video presents percentage in a playful way.

Practical Activity: "Percentage in Practice: The Business World"

Project Objective

• Understand and apply percentage concepts in solving concrete and everyday problems.
• Collaborative demonstration of understanding through the creation of a small business venture.
• Develop teamwork skills, time management, proactivity, and creative thinking.

Detailed Project Description

Students, divided into groups of 3 to 5 people, will create a "mini company". Each group will be responsible for planning and simulating the operations of a company of their interest (e.g. clothing store, restaurant, game producer, etc.).

The activities will involve defining products or services, calculating production or supply costs, determining selling prices, calculating profits, taxes, discounts, and promotions. All using percentage concepts!

In addition, the groups will need to produce reports on fictitious sales, interpret and analyze this data expressed in percentages.

The project will last for four weeks.

Necessary Materials

1. Computer with internet access
2. Text editing and spreadsheet programs (Microsoft Office, Google Docs)
3. Presentation materials (cardboards, brushes, images, etc. - depending on the group's preference)

Detailed Step-by-Step for Activity Execution

1. Week 1: Group formation and choice of business type. During this week, students should research the market, competition, target audience, and products or services to be sold.

2. Week 2: Financial planning. Here, production or supply costs of the product/service should be calculated, selling prices determined, and possible profits calculated. All of this using percentage concepts!

3. Week 3: Sales simulation and business-related activities. The groups must simulate sales situations (with discounts and promotions), tax calculations, profit analysis. Also in this stage, the groups must produce sales reports.

4. Week 4: Results analysis and preparation of a presentation. The groups will review the results of the simulated sales, interpret the collected data, and express them in percentages (e.g. increase or decrease in sales, profit percentage, etc.). Finally, the groups will prepare a presentation of their business and results for the class.

Project Deliverables

1. Activity Reports: Throughout the project, students must produce weekly reports of their activities, progress, and difficulties. These reports should include the calculations performed and the percentages obtained.

2. Final Presentation: At the end of the project, each group must present their business to the class. The presentation should include a description of the business, financial planning, sales simulations, and results analysis.

3. Written Document: After the presentation, the group must produce a final report in a written document format. This report should follow the proposed format: Introduction (contextualization of the theme, relevance, project objective), Development (theory behind the theme, detailed description of the activity, methodology used, results obtained), and Conclusion (summary of the main points, lessons learned, conclusions about the project). In addition, it should contain the Bibliography used for research and project implementation. This document will serve as a record of the students' learning process and will be used to assess the understanding and application of the studied concepts.