Counting zero means starting your counting from the number zero. When we say counting, we are talking about the numbers we say when we go in order like 1, 2, 3, 4, and so on. Instead of starting from 1, counting zero means you start from the very beginning, which is zero. It's like when we play a game and the count starts from zero instead of one. So, for example, if you're counting zero to 5, you'd say: 0, 1, 2, 3, 4, 5. Just remember, when you're counting zero, you start from nothing, which is zero.