Arithmetic Operations, Function Calls, Recursion and more in Ruby, Ruby

Language: Layout:

'''
Ruby is a language that is pretty similar to Python. If you know python then you can easily get a grasp of this language.

You will be "Fast as Fuck boiii".
For me it took me 1-2 hours to get a grasp of this languages. You can do this.

This program demonstrates stuff like: Getting user input, Function declaration, Class declaration, Recursion, and a bit of String Formatting.
Hope you will understand this program.

Thanks for reading.

PROGRAM BY \'JAMES COLLINS\'
'''

class Arithmetic # This is class...  I don't know what else to say.

def add(num1, num2) # Function to add the given numbers.
		return num1 + num2
	end
  
    def diff(num1, num2) # Function to find the difference between the given numbers and return their absolute value.
		return (num1 - num2).abs
	end
	
    def multi(num1, num2) # Function to find the product of the given numbers.
		return num1 * num2
	end
	
    def div(num1, num2) # Function to divide the 2 given numbers and return the quotient as a float.
		return (num1 / (num2 * 1.0))
	end
	
    def factorial(num) # Function to return the factorial of the given numbers. 
        if num == 0
            return 1
        elsif num >= 1
            return num * factorial(num - 1)
		elsif num < 0
            return "\'Doesn't exist.\'"
		end
	end
end

num1 = gets.to_i # Getting the user input and converting it to int.
num2 = gets.to_i # Getting the second number as string and converting it to int.
obj = Arithmetic.new # Initialising the a new "Arithmetic" object.

puts("Sum = #{obj.add num1, num2 }")
puts("Difference = #{obj.diff num1, num2 }")
puts("Product = #{obj.multi num1, num2 }")
puts("Quotient = #{obj.div num1, num2 }")
puts("Factorial = #{obj.factorial num1 }")

#PROGRAM BY 'JAMES COLLINS'

[ - ] Show input
Absolute running time: 0.27 sec, cpu time: 0.15 sec, memory peak: 8 Mb, absolute service time: 0,37 sec