Arithmetic Operators

Arithmetic operators perform mathematical operations such as addition, subtraction, multiplication, and division.

When values, variables, or objects are connected using arithmetic operators, the result is an arithmetic expression.

a = 10
b = 3

print(a + b)

13

Visual reference

10 + 3 becomes the arithmetic expression 13.

What you'll learn

• The seven arithmetic operators
• Why / always returns a float quotient
• How // behaves with integers and floats
• Finding square roots using ** 0.5

The seven arithmetic operators

Symbol	Meaning	Example	Result
+	Addition	10 + 3	13
-	Subtraction	10 - 3	7
*	Multiplication	10 * 3	30
/	True division	10 / 3	3.333…
//	Floor division	10 // 3	3
%	Modulo	10 % 3	1
**	Exponentiation	10 ** 3	1000

Interactive playground

Understanding / vs //

True division (/)

print(10 / 3)

3.3333333333333335

Floor division (//)

print(10 // 3)

3

The // operator removes the fractional part by taking the floor of the result.

What happens when floats are involved?

Even with //, if either operand is a float, the result is still a float type.

Expression	Result	Type
10 / 3	3.3333333333333335	float
10 // 3	3	int
10.0 // 3.0	3.0	float
10 // 3.0	3.0	float

print(10.0 / 3.0)
print(10.0 // 3.0)
print(10.0 / 3)
print(10.0 // 3)
print(10 / 3.0)
print(10 // 3.0)

3.3333333333333335
3.0
3.3333333333333335
3.0
3.3333333333333335
3.0

Exponentiation (**)

The ** operator raises a number to a power.

print(10 ** 3)
print(2 ** 5)

1000
32

Read 10 ** 3 as “10 to the power of 3.”

Square root using ** 0.5

n = 16
print(n ** 0.5)

4.0

Use the interactive block above to try other values, or run 81 ** 0.5 in the playground.

Interactive program (two numbers)

This version uses input() to read values from the keyboard.

a = int(input("Enter value of a: "))
b = int(input("Enter value of b: "))

print("sum({}, {}) = {}".format(a, b, a + b))
print("div({}, {}) = {}".format(a, b, a / b))
print("floor_div({}, {}) = {}".format(a, b, a // b))
print("pow({}, {}) = {}".format(a, b, a ** b))

Example input: 10 and 3.

Practice exercises

1. Predict the output of 10 // 3 and 10 / 3 before running.
2. Predict the result of 10.0 // 3.
3. Print the square root of 81 using 81 ** 0.5.

Quick knowledge check

1. What does / return?
   A float quotient.

2. What is 10 // 3?
   3

3. What is 10.0 // 3?
   3.0

Summary

• Python has seven arithmetic operators: +, -, *, /, //, %, **.
• / always performs true division and returns a float.
• // performs floor division; with floats, the result remains a float.
• ** is used for powers; ** 0.5 gives a compact square root.

Next lesson: Assignment Operator — =, multi-target assignment, and swapping variables.