Numbers and Math

Python is excellent for working with numbers. It provides robust support for numerical operations, from basic arithmetic to more advanced math.

Number Types in Python

  1. Integers (int): Whole numbers (positive or negative). 
    x = 10  # Integer
y = -5  # Negative integer
  2. Floating-Point Numbers (float): Numbers with a decimal point. 
    pi = 3.14159  # Float
result = -0.5  # Negative float
  3. Complex Numbers (complex): Numbers with a real and imaginary part. 
    z = 2 + 3j  # Complex number

Basic Arithmetic Operations

Python supports standard arithmetic operators:

Operator Description Example Result
+ Addition 5 + 3 8
- Subtraction 10 - 4 6
* Multiplication 2 * 3 6
/ Division (float) 7 / 2 3.5
// Floor Division 7 // 2 3
% Modulus (remainder) 7 % 2 1
** Exponentiation 2 ** 3 8

Examples:

a = 15
b = 4

print(a + b)  # 19
print(a - b)  # 11
print(a * b)  # 60
print(a / b)  # 3.75
print(a // b) # 3
print(a % b)  # 3
print(a ** b) # 50625

Built-in Math Functions

Python provides several built-in functions for working with numbers:

Function Description Example Result
abs(x) Absolute value abs(-5) 5
round(x, n) Round to n decimal places round(3.14159, 2) 3.14
max(x, y) Maximum value max(3, 7) 7
min(x, y) Minimum value min(3, 7) 3
pow(x, y) Raise x to the power of y pow(2, 3) 8

The math Module

For advanced mathematical operations, Python includes the math module.

Using the math Module:

import math

print(math.sqrt(16))  # 4.0
print(math.pi)        # 3.141592653589793
print(math.sin(math.radians(90)))  # 1.0

Common math Functions:

Function Description Example
math.sqrt(x) Square root of x math.sqrt(9) → 3.0
math.pi Value of π math.pi → 3.14159...
math.sin(x) Sine of x (in radians) math.sin(math.pi/2) → 1.0
math.cos(x) Cosine of x (in radians) math.cos(0) → 1.0
math.log(x) Natural logarithm of x math.log(10) → 2.302...

Practice Exercises

  1. Write a Python script to:
    • Add, subtract, multiply, and divide two numbers.
    • Use floor division and modulus to find the quotient and remainder.
  2. Use the math module to calculate:
    • The square root of 64.
    • The sine of 45 degrees.
  3. Round the number 7.56789 to 2 decimal places.

With these tools, you can confidently handle numerical operations in Python!

Next Lesson: Strings