Solving Math Word Problems: How Many Boys Are in the Class?

Word problems are a common type of math question that students and adults often encounter. These problems require you to apply mathematical concepts to real-life scenarios. In this article, we will explore a typical problem and solve it step-by-step using different methods. Let's dive into the example provided.

Problem Statement

A class has 45 students out of which (frac{5}{9}) are girls. How many boys are in their class?

Method 1: Algebraic Approach

Let's denote the number of boys in the class as x. According to the problem, the fraction of girls in the class is (frac{5}{9}). Therefore, the number of girls can be expressed as (frac{5}{9} times 45).

Calculate the number of girls:

(frac{5}{9} times 45 25)

Since the total number of students is 45, the number of boys can be found by subtracting the number of girls from the total number of students:

(text{Number of boys} 45 - 25 20)

Therefore, there are 20 boys in the class.

Method 2: Basic Subtraction

This approach simplifies the problem by focusing on the numbers directly.

Start by calculating the number of girls: (frac{5}{9} times 45 25). Subtract the number of girls from the total number of students: (45 - 25 20).

Again, we find that there are 20 boys in the class.

Method 3: Simplified Calculation

This method uses a more straightforward calculation where the steps are broken down for clarity.

Note that the fraction of girls is (frac{5}{9}). To find the number of girls, multiply (45) by (frac{5}{9}) to get (25). Subtract the number of girls from the total number of students: (45 - 25 20).

The number of boys in the class is 20.

Conclusion

Solving math word problems can be as simple as identifying the relevant information and applying basic arithmetic operations. Whether you use algebraic expressions or direct calculations, the goal is to break down the problem into manageable steps. In this case, we found that there are 20 boys in the class with various approaches.

For more practice and to improve your problem-solving skills, try applying these methods to other math word problems. Understanding the underlying concepts and practicing regularly will enhance your problem-solving abilities.

Key Takeaways:

Identify the given information and the unknown variable. Use fractions and arithmetic operations to find the unknown. Verify your solution by checking the total number of students.