Python Program to Find the LCM of Two Numbers

1. Introduction

The Least Common Multiple (LCM) of two numbers is the smallest number that is a multiple of both numbers. Finding the LCM is important for operations involving fractions and for solving equations in algebra. Python can compute the LCM efficiently with a function that embodies the logic behind this mathematical concept.

2. Program Steps

1. Define two numbers to find the LCM of.

2. Calculate the Greatest Common Divisor (GCD) of the two numbers.

3. Use the relationship between GCD and LCM: LCM(a, b) = |a * b| / GCD(a, b).

4. Print the LCM.

3. Code Program

LCM is used in arithmetic to find the smallest common multiple that two or more numbers have. The LCM of two non-zero integers, a and b, is the smallest positive integer that is divisible by both a and b.
import math

# Function to find the LCM of two numbers
def find_lcm(num1, num2):
    # Calculate the LCM using the GCD
    lcm = abs(num1 * num2) // math.gcd(num1, num2)
    return lcm

# Numbers to find the LCM of
number1 = 12
number2 = 18
# Calculate the LCM
lcm_result = find_lcm(number1, number2)
# Print the LCM
print(f"The LCM of {number1} and {number2} is: {lcm_result}")


The LCM of 12 and 18 is: 36


1. The math module's gcd function is used to compute the Greatest Common Divisor of two numbers, which is required to calculate the LCM.

2. find_lcm is a function that accepts two integers, num1 and num2.

3. The function computes the LCM by multiplying the absolute values of num1 and num2 and then dividing by the GCD of num1 and num2.

4. The // operator is used for integer division to ensure the result is an integer.

5. number1 and number2 are initialized with the values 12 and 18, respectively.

6. The find_lcm function is called with these numbers and stores the result in lcm_result.

7. The output is generated using an f-string and shows that the LCM of 12 and 18 is 36.