Understanding Arithmetic Operators in C

Arithmetic operators are fundamental components in any programming language, enabling developers to perform mathematical calculations. In C, these operators are straightforward but extremely powerful, providing the necessary tools to execute basic arithmetic operations. In this blog post, we'll explore each arithmetic operator in C, illustrating their usage with examples.

#### The Basics

C offers a variety of arithmetic operators, including addition, subtraction, multiplication, division, and modulus. Here’s a quick rundown:

1. **Addition (`+`)**

2. **Subtraction (`-`)**

3. **Multiplication (`*`)**

4. **Division (`/`)**

5. **Modulus (`%`)**

#### Addition (`+`)

The addition operator is used to add two operands.

**Example:**

```c

#include <stdio.h>

int main() {

int a = 5;

int b = 3;

int sum = a + b;

printf("Sum: %d\n", sum); // Output: Sum: 8

return 0;

}

```

In this example, the integers `a` and `b` are added together, and the result is stored in `sum`.

#### Subtraction (`-`)

The subtraction operator subtracts the second operand from the first.

**Example:**

```c

#include <stdio.h>

int main() {

int a = 5;

int b = 3;

int difference = a - b;

printf("Difference: %d\n", difference); // Output: Difference: 2

return 0;

}

```

Here, `b` is subtracted from `a`, and the result is stored in `difference`.

#### Multiplication (`*`)

The multiplication operator multiplies two operands.

**Example:**

```c

#include <stdio.h>

int main() {

int a = 5;

int b = 3;

int product = a * b;

printf("Product: %d\n", product); // Output: Product: 15

return 0;

}

```

In this code, `a` is multiplied by `b`, and the result is stored in `product`.

#### Division (`/`)

The division operator divides the first operand by the second. Note that if both operands are integers, the result will also be an integer (fractional part discarded).

**Example:**

```c

#include <stdio.h>

int main() {

int a = 10;

int b = 3;

int quotient = a / b;

printf("Quotient: %d\n", quotient); // Output: Quotient: 3

return 0;

}

```

Here, `a` is divided by `b`, and the result (quotient) is stored in `quotient`. Since both `a` and `b` are integers, the fractional part is discarded.

#### Modulus (`%`)

The modulus operator returns the remainder of the division of the first operand by the second. This operator is only applicable to integers.

**Example:**

```c

#include <stdio.h>

int main() {

int a = 10;

int b = 3;

int remainder = a % b;

printf("Remainder: %d\n", remainder); // Output: Remainder: 1

return 0;

}

```

In this example, `a` is divided by `b`, and the remainder is stored in `remainder`.

#### Combined Example

Let’s combine all these operators into a single example to see how they work together.

```c

#include <stdio.h>

int main() {

int a = 12;

int b = 5;

int sum = a + b;

int difference = a - b;

int product = a * b;

int quotient = a / b;

int remainder = a % b;

printf("Sum: %d\n", sum); // Output: Sum: 17

printf("Difference: %d\n", difference); // Output: Difference: 7

printf("Product: %d\n", product); // Output: Product: 60

printf("Quotient: %d\n", quotient); // Output: Quotient: 2

printf("Remainder: %d\n", remainder); // Output: Remainder: 2

return 0;

}

```

In this program, we perform all five arithmetic operations using the same pair of numbers, `a` and `b`, and print out the results.

Here are five programming assignments focusing solely on arithmetic operations in C, with the last one now involving compound interest calculations.

### Assignment 1: Calculating the Perimeter and Area of a Rectangle

**Objective:**

Write a program that calculates the perimeter and area of a rectangle given its length and width.

**Instructions:**

1. Prompt the user to enter the length and width of the rectangle.

2. Calculate the perimeter using the formula: `Perimeter = 2 * (length + width)`.

3. Calculate the area using the formula: `Area = length * width`.

4. Print the perimeter and area.

### Assignment 2: Converting Days to Weeks and Days

**Objective:**

Write a program that converts a given number of days into weeks and days.

**Instructions:**

1. Prompt the user to enter a number of days.

2. Calculate the number of weeks and remaining days.

- Weeks can be calculated using integer division (`days / 7`).

- Remaining days can be calculated using the modulus operator (`days % 7`).

3. Print the number of weeks and remaining days.

### Assignment 3: Simple Interest Calculator

**Objective:**

Write a program that calculates simple interest given the principal, rate of interest, and time period.

**Instructions:**

1. Prompt the user to enter the principal amount, rate of interest, and time period in years.

2. Calculate the simple interest using the formula: `Simple Interest = (Principal * Rate * Time) / 100`.

3. Print the calculated simple interest.

### Assignment 4: Calculating the Average of Four Numbers

**Objective:**

Write a program that calculates the average of four numbers.

**Instructions:**

1. Prompt the user to enter four integers.

2. Calculate the sum of the four integers.

3. Compute the average by dividing the sum by 4.

4. Print the average.

### Assignment 5: Compound Interest Calculator

**Objective:**

Write a program that calculates compound interest given the principal, rate of interest, time period, and number of times interest is compounded per year.

**Instructions:**

1. Prompt the user to enter the principal amount, rate of interest (as a percentage), time period in years, and the number of times the interest is compounded per year.

2. Calculate the compound interest using the formula:

A = P \left(1 + \frac{r}{n}\right)^{nt}

where:

- \( P \) is the principal amount,

- \( r \) is the annual interest rate (decimal),

- \( n \) is the number of times interest is compounded per year,

- \( t \) is the time the money is invested for in years,

- \( A \) is the amount of money accumulated after n years, including interest.

3. Print the final amount including interest.

These assignments will help you practice various arithmetic operations and concepts, including the calculation of simple and compound interest, using different arithmetic operators, and performing basic arithmetic tasks in C. Happy coding!