test.rb

@filled = {
  'num1' => 1, 'num2' => 2, 'num3' => 3,
  'num4' => 4, 'num5' => 5, 'num6' => 6,
  'num7' => 7, 'num8' => 8, 'num9' => 9
}

selected = @filled.to_a.select { |e| e[1] != 'text' }

while selected.any?
  number = rand(9)

  @filled["num#{number + 1}"] = 'text'

  selected = @filled.to_a.select { |e| e[1] != 'text' }
  puts @filled
end