Write A C++ Program To Find The Sum And Product Of Two Numbers

In this article, you will learn how to write a C++ program that takes two numbers as input from the user and calculates their sum and product. This fundamental exercise introduces basic input/output operations and arithmetic calculations in C++.

Problem Statement

Many programming tasks involve basic arithmetic operations on numerical data. A common requirement is to accept two distinct numbers and perform fundamental calculations like addition and multiplication, then display the results. This forms the basis for more complex data processing.

Example

Consider two numbers, 5 and 3. The program should compute:

• Sum: 5 + 3 = 8
• Product: 5 \* 3 = 15

Background & Knowledge Prerequisites

To understand this program, you should be familiar with:

• C++ Basic Syntax: Understanding how to write simple C++ statements.
• Variables: How to declare and use integer (int) or floating-point (float, double) variables to store numbers.
• Input/Output Operations: Using std::cout for printing output to the console and std::cin for reading input from the user.
• Arithmetic Operators: Basic operators like + for addition and * for multiplication.

Use Cases

Calculating the sum and product of numbers is a foundational operation with wide applications:

• Financial Calculations: Summing expenses or revenues, calculating compound interest (which often involves products).
• Geometry: Calculating the area of a rectangle (product of length and width) or perimeter (sum of sides).
• Data Analysis: Basic statistical aggregates like sums, or products in certain probability calculations.
• Game Development: Calculating scores (summing points) or scaling object sizes (product with a factor).
• Engineering: Simple unit conversions or calculating total load.

Solution Approaches

For calculating the sum and product of two numbers, the most straightforward and universally applicable approach involves direct arithmetic operations after reading input.

Direct Calculation

This approach involves reading two numbers from the user, performing the addition and multiplication operations, and then displaying the results.

• Summary: Read two integer values, compute their sum and product, and print these results to the console.

// Sum and Product of Two Numbers
#include <iostream> // Required for input/output operations

int main() {
    // Step 1: Declare two integer variables to store the input numbers.
    int num1, num2;

    // Step 2: Prompt the user to enter the first number.
    std::cout << "Enter the first number: ";
    // Step 3: Read the first number from the user and store it in num1.
    std::cin >> num1;

    // Step 4: Prompt the user to enter the second number.
    std::cout << "Enter the second number: ";
    // Step 5: Read the second number from the user and store it in num2.
    std::cin >> num2;

    // Step 6: Calculate the sum of the two numbers.
    int sum = num1 + num2;

    // Step 7: Calculate the product of the two numbers.
    int product = num1 * num2;

    // Step 8: Display the calculated sum.
    std::cout << "Sum: " << sum << std::endl;

    // Step 9: Display the calculated product.
    std::cout << "Product: " << product << std::endl;

    // Step 10: Indicate successful program execution.
    return 0;
}

Run

• Sample Output

Enter the first number: 10
Enter the second number: 5
Sum: 15
Product: 50

• Stepwise Explanation

1. #include : This line includes the iostream library, which provides functionalities for input (from keyboard) and output (to screen).
2. int main() { ... }: This is the main function where the program execution begins.
3. int num1, num2;: Declares two integer variables, num1 and num2, to hold the numbers entered by the user. Using int is suitable for whole numbers; for decimals, float or double could be used.
4. std::cout << "Enter the first number: ";: Displays a message on the console, prompting the user to input the first number. std::cout is used for output.
5. std::cin >> num1;: Reads the integer value entered by the user from the console and stores it in the num1 variable. std::cin is used for input.
6. The same process is repeated for the second number (num2).
7. int sum = num1 + num2;: Calculates the sum of num1 and num2 and stores the result in a new integer variable named sum.
8. int product = num1 * num2;: Calculates the product of num1 and num2 and stores the result in a new integer variable named product.
9. std::cout << "Sum: " << sum << std::endl;: Prints the string "Sum: " followed by the value stored in the sum variable. std::endl moves the cursor to the next line.
10. std::cout << "Product: " << product << std::endl;: Prints the string "Product: " followed by the value stored in the product variable.
11. return 0;: Indicates that the program has executed successfully.

Conclusion

This article demonstrated how to write a simple C++ program to find the sum and product of two user-provided numbers. By using basic input/output operations and arithmetic operators, you can efficiently perform fundamental calculations. This serves as a building block for more complex C++ applications involving numerical data.

Summary

• C++ programs can interact with users for input using std::cin.
• Output to the console is handled by std::cout.
• Arithmetic operators like + (addition) and * (multiplication) are used for calculations.
• Variables must be declared with appropriate data types (e.g., int for integers) before use.
• The main function is the entry point for all C++ programs.