Largest Prime

largest-prime.rb

# Euler problem 3
# used my old prime method from school week 1

class LargestPrime
  def largest(number)
    Math.sqrt(number).to_i.downto(2) do |i|
      # prime factor is a prime number that divides the integer exactly
      return i if number % i == 0 && prime?(i)
    end
  end
  def prime?(number)
      (2..Math.sqrt(number)).each { |i| return false if number % i == 0}
      true
  end
end