This problem can be solved by pre-school children...

#!/usr/bin/env ruby
# Solution for:
#   This problem can be solved by pre-school children in 5-10 minutes,
#   by programmers - in 1 hour, by people with higher education...
#   well, check it yourself :)
def enigma array
  array.each do |x|
    print "#{enigma2(x)} "
  end
  puts
end

def enigma2 x
  i=0
  x.each_char do |y|
    case Integer(y)
      when 0,6,9
        i+=1
      when 8
        i+=2
    end
  end
  i
end

zero=['7111','2172','1111','3213','2222','3333','5555','7777','5531']
one=['9313','7756']
two=['7662']
three=['8193','6855']
four=['6666','0000','9999']
five=['8096','9881']
six=['8809']
unknown=['2581']

enigmas=[zero,one,two,three,four,five,six,unknown]
enigmas.each do |x|
  enigma x
end