As you may notice, this is a balanced system. At the end of a deck the count should be zero. A good drill to practice is to get a deck of cards, turn them over one by one, and keep track of the count. If you enter a game mid-way between the deck or shoe, flat bet until the cards are shuffled. Once the cards are shuffled commence counting from zero.
Lets do a quick example using ten cards.
The next card is the 7 which is zero so disregard it. The next card is another ten, giving a total count of -2. The next card is a nine which has a value of zero so ignore it, total count is still at -2. Next is a ten, total count is at -3. So at the end of a hand of ten cards dealt to 2 players and the dealer, the point count is minus two.