Bill Calculator - OOP approach

tip.rb

class Tip
  attr_reader :tip
  def initialize(bill, tip)
    @bill = bill
    @tip = tip
  end

  def get_amount
    @bill_amount = @bill.to_i
    if @bill_amount == 0
      puts "Please specify a valid number for the bill amount:"
    end
    if @bill_amount < 0 
      puts "Please specify a positive number"
    end
    @bill_amount 
  end

  def total_amount
    tip = @bill_amount / 100 * @tip
    total = @bill_amount + tip 
    total
  end
end

t = Tip.new(100, 50)
puts "The bill is £#{t.get_amount}"
puts "The tip is #{t.tip}%"
puts "The total amount is £#{t.total_amount}"