Ruby program to check the armstrong number

Write a Ruby program to check the armstrong number

Example of armstrong number:
Input - 153
Output - 1^3 + 5^3 + 3^3 = 153, so it is Armstrong no.

class ArmstrongNumber

  def checkArmstrong

    print "Enter the number: "

    input_num = gets.chomp.to_i

    num = input_num

    check = 0 

    while (num > 0) do 

      rem = num % 10 

      num = num / 10 

      check = check + (rem * rem * rem)

    end

    if check == input_num

      print "#{input_num} is an armstrong number"

    else

      print "#{input_num} is not an armstrong number"

    end 

  end

end

p = ArmstrongNumber.new 

p.checkArmstrong

Output:

Enter the number:  371
371 is an armstrong number