for your second batch, falling within 0.009 of your target gravity isnt just good, its impressive
also, there are temperature conversion factors for what the temperature of the sample is when you take the gravity and how that temperature changes the gravity reading
the hotter a wort sample is, the more you need to add to the reading to correct it (and also the more inaccurate it becomes)
ALWAYS take the temperature of you wort when taking gravity- i stick the probe from a probe thermometer into the graduated cylind along with the hydrometer so i always know- it may not stay the same temp as the brew in the kettle for long
all-in-all, i'd say that you did a damned fine job for your second brew- not pro-league accuracy, but if 0.009 off of OG is your biggest problem brewing right now, you are destined for great things!