app.rb

INFINITY = 1.to_f / 0

def spaced(s)
  s.scan(/.{1,5}/).join(' ')
end

10.times do

  a = b = INFINITY

  loop do
    a = rand(0..10)
    b = rand(0..10)
    break if a + b <= 10
  end

  puts "#{a} + #{b} = "
  puts
  puts "#{spaced('.' * a)} + #{spaced('.' * b)} ="
  puts
  puts

end