Contextualization

Hello, little mathematicians! Have you heard about subtraction? It is a very important mathematical operation that helps us solve many problems in our daily lives. For example, when you go to the store with your mom and she gives you $10.00 to buy a toy that costs $5.00, you need to do a subtraction to know how much money will be left, right?

We have already learned that mathematics is like a language that helps us understand the world around us. Subtraction is an important part of this language and, once we master it, we can solve many everyday situations more quickly and efficiently.

Introduction

Subtraction is a mathematical operation that compares two numbers, called minuend and subtrahend, and gives us the difference between them. In the store example, the minuend would be the amount that mom gave you, that is, $10.00, and the subtrahend would be the value of the toy, $5.00. The difference, or the result of the subtraction, would be the amount left, $5.00.

To solve a subtraction, we use the minus sign (-) between the minuend and the subtrahend. So, the subtraction of $10.00 - $5.00 would look like this: $10.00 - $5.00 = $5.00.

You may have noticed that the order of the numbers in subtraction is very important. If we reverse the order, the result also changes. For example, if we subtract $5.00 - $10.00, the result will not be the same. Do you know why?

In this project, we will explore more about subtraction and its properties, as well as practice a lot to become true masters in this operation. Let's go, little mathematicians!

Practical Activity: "Subtraction Hunt"

Project Objective

The objective of this project is to provide students with the opportunity to explore and better understand the concept of subtraction, its properties, and applications in everyday life in a fun and practical way. In addition, the project aims to stimulate teamwork, creativity, problem-solving, and communication among students.

Project Description

In this activity, students will be challenged to create a "word search" with various subtraction problems. Each group will develop their own word search, which will be solved by other groups. This way, students will not only practice solving subtractions but also create problems and solutions, exercising mathematical thinking and communication skills.

Required Materials

• A4 paper or cardboard for creating the word search
• Pencil or pen to write the problems and solutions
• Ruler to help draw the word search
• Dictionary (optional, to help with the writing of hidden words)

Step by Step

1. Group Formation: Divide the class into groups of 3 to 5 students. Each group will be responsible for creating a subtraction word search.

2. Elaboration of Subtraction Problems: Each group should create 10 subtraction problems suitable for the 2nd-grade level of Elementary School. The problems should contain numbers from 1 to 20 and be written in a clear and understandable language. For example: "There were 15 balloons at the party. John took 7 balloons. How many balloons are left at the party?"

3. Creation of the Word Search: On an A4 paper or cardboard, students will create the word search, which should contain the answers to the subtraction problems hidden. The words can be horizontal, vertical, or diagonal, and can be reversed. Students should make sure that the word search is neither too easy nor too difficult.

4. Word Search Exchange: After completing the creation of the word search, groups will exchange their work with each other.

5. Solving the Word Searches: Each group must solve the word search they received. To do this, they will have to find the answers to the subtraction problems hidden in the word search.

6. Presentation of Results: After solving the word search, each group must present their answers to the group that created the word search. They should explain how they found the answers and if they had any difficulties.

7. Classroom Discussion: At the end of the activity, everyone should gather for a classroom discussion. Each group will have the opportunity to share their experiences, difficulties, and learnings. The teacher will mediate the discussion and clarify any doubts about the concept of subtraction.

Remember that collaboration and creativity are key points for the success of this project. Have fun learning about subtraction!