aboutscoring.rb

def score(dice)
  return 0 if dice.empty?
  counts = Hash.new(0)
  dice.each do |die|
    counts[die] += 1
  end
  a_set = (counts.select {|k, v| v > 2})
  set = a_set[0][0] if a_set.empty? == false

  counts[set] -= 3 if set != nil

  score = 0
  if set == 1
    score += 1000
    score += credit_ones_and_fives(counts)
  elsif set == 5
    score += 500
    score += credit_ones_and_fives(counts)
  elsif set != nil
    score += set * 100
    score += credit_ones_and_fives(counts)
  else
    score += credit_ones_and_fives(counts)
  end

end

def credit_ones_and_fives(counts)
  score = 0
  score += counts[1] * 100
  score += counts[5] * 50
end

Refactored to use a hash and a helper method for the common math