As I am sure you have all seen before in movies such as 21, there is much more to counting cards than adding and subtracting. The art of card counting takes years to master, but I am going to share with you a trick that makes it much easier.
Remembering the count is going to be your toughest challenge as it is very easy to lose concentration. This is why you should associate words with numbers.
Card Counting Tricks of the Trade
+1 = Tree (only one tree in a field of grass)
+2 = Switch (on and off)
+3 = Stool (has three legs)
+4 = Car (four wheels)
+5 = Glove (five fingers)
+6 = Gun (six rounds)
+7 = Craps
+8 = Pool (the black 8 ball)
+9 = Cat (cat has nine lives)
+10 = Bowling (ten pins)
+11 = Football
+12 = Eggs (a dozen eggs in a basket)
+13 = Witch
+14 = Ring (14k gold)
+15 = Paycheck (15th and 30th of every month)
+16 = Sweet
+17 = Magazine (the magazine "Seventeen")
+18 = Voting booth (have to be 18 to vote)
Instead of trying to remember the count in number form (which gets mentally exhausting and leads to error), say a sentence to yourself after each hand. For example, if the count is +10 you can say to yourself, "maybe I will go bowling after this". Don't say it out loud of course or they might think something up! This trick will really help your card counting skills evolve to the next level.
Finally, you can use the same words if the count is negative because that part is not difficult to remember. In other words, you will always know whether the count is positive or negative, but the number remembering is tricky. Hopefully this helps all of you aspiring card counters. Good luck!