Welcome to Day 8 of 100 Days of Python!

In Day 7, I was given my first Python exercise:

Create a calculator capable of performing addition, subtraction, multiplication, and division on two numbers and display the output in a readable format.

Today, we will look at the solution and understand how the program works.

The calculator uses variables, arithmetic operators, and the print() function.

---

1. The Calculator

Here is the solution:

a = 7
b = 3

print("Addition of", a, "and", b, "is:", a + b)
print("Subtraction of", a, "and", b, "is:", a - b)
print("Multiplication of", a, "and", b, "is:", a * b)
print("Division of", a, "and", b, "is:", a / b)

print("Floor Division of", a, "and", b, "is:", a // b)
print("Modulus of", a, "and", b, "is:", a % b)
print("Exponentiation of", a, "and", b, "is:", a ** b)

---

2. Understanding the Variables

First, we create two variables:

a = 7
b = 3

Here:

• a stores the value 7

• b stores the value 3

These two variables are used as the operands for our calculations.

---

3. Addition

print("Addition of", a, "and", b, "is:", a + b)

The + operator performs addition.

Since:

7 + 3 = 10

The output is:

Addition of 7 and 3 is: 10

---

4. Subtraction

print("Subtraction of", a, "and", b, "is:", a - b)

The - operator performs subtraction.

7 - 3 = 4

Output:

Subtraction of 7 and 3 is: 4

---

5. Multiplication

print("Multiplication of", a, "and", b, "is:", a * b)

The * operator performs multiplication.

7 × 3 = 21

Output:

Multiplication of 7 and 3 is: 21

In Python, multiplication is written using *.

---

6. Division

print("Division of", a, "and", b, "is:", a / b)

The / operator performs regular division.

7 / 3 = 2.3333333333333335

Output:

Division of 7 and 3 is: 2.3333333333333335

Python returns a floating-point value when using /.

---

7. Floor Division

Although floor division was not one of the four required operations in the original exercise, I also included it for additional practice.

print("Floor Division of", a, "and", b, "is:", a // b)

The // operator performs floor division.

7 // 3 = 2

Output:

Floor Division of 7 and 3 is: 2

---

8. Modulus

The % operator returns the remainder after division.

print("Modulus of", a, "and", b, "is:", a % b)

Since:

7 ÷ 3 = 2 remainder 1

We get:

7 % 3 = 1

Output:

Modulus of 7 and 3 is: 1

---

9. Exponentiation

The ** operator performs exponentiation.

print("Exponentiation of", a, "and", b, "is:", a ** b)

This means:

7 ** 3
= 7 × 7 × 7
= 343

Output:

Exponentiation of 7 and 3 is: 343

---

10. Complete Output

When the complete program is executed, the output will be:

Addition of 7 and 3 is: 10
Subtraction of 7 and 3 is: 4
Multiplication of 7 and 3 is: 21
Division of 7 and 3 is: 2.3333333333333335
Floor Division of 7 and 3 is: 2
Modulus of 7 and 3 is: 1
Exponentiation of 7 and 3 is: 343

---

11. What We Used

This small calculator combines several concepts learned in the previous days.

Variables

a = 7
b = 3

Variables store the values that we want to use.

Arithmetic Operators

+   Addition
-   Subtraction
*   Multiplication
/   Division
//  Floor Division
%   Modulus
**  Exponentiation

print()

The print() function displays the operation and its result in a readable format.

For example:

print("Addition of", a, "and", b, "is:", a + b)

This combines text, variables, and an arithmetic expression in one statement.

---

12. Exercise Completed

The original exercise required:

• Addition

• Subtraction

• Multiplication

• Division

• Readable output

The solution successfully performs all four required operations.

I also added:

• Floor Division

• Modulus

• Exponentiation

as additional practice with the arithmetic operators learned in Day 7.

---

13. Quick Revision

Operation	Python Operator	Example	Result
Addition	+	7 + 3	10
Subtraction	-	7 - 3	4
Multiplication	*	7 * 3	21
Division	/	7 / 3	2.333...
Floor Division	//	7 // 3	2
Modulus	%	7 % 3	1
Exponentiation	**	7 ** 3	343

---

14. Key Takeaways

After completing this exercise, I can now:

• Store numbers in variables

• Perform basic arithmetic operations

• Use Python arithmetic operators

• Combine variables and operators in expressions

• Display calculation results using print()

• Format output so that it is easier to read

• Understand the difference between / and //

• Understand how % returns a remainder

• Use ** for exponentiation

This is a very small program, but it is an important first step toward building larger Python programs.

Day 7 gave me the problem. Day 8 gave me the solution.

The next step is to keep building on these fundamentals and gradually make the programs more interactive and useful.

---

📂 Day 8 Resources

All notes and code for this day are available in the GitHub repository:

https://github.com/SriteshSuranjan/100-Days-of-Python/tree/main/08-Day8-Exercise-1-Create-a-Calculator-Solution

---