Counting counting, matching things one by one to a sequence of number-words or marks, is one of the first ways we bring order to the world. You have three stones. You have five fingers. You say one, two, three. The order matters. The same sequence works for stones, fingers, or days. Counting gives us a way to compare without holding everything in our hands at once. First, we decide what to count. Then we go through them in a fixed order, saying or marking one number for each. When we finish, the last number is how many there are. That seems simple. But it rests on something deep: the idea that we can treat different things as equivalent for a purpose. Three apples and three oranges are both "three." Counting is a tool that works across many domains. Counting can be wrong. We can skip one, or count one twice, or lose our place. So cultures have invented ways to check: grouping by fives or tens, making notches on a stick, moving pebbles from one pile to another. These are the ancestors of writing and of mathematics. When knowledge is lost, counting is often one of the first things people try to recover—because so much else depends on it. How do you know you have counted correctly? What would you do if you had no words for numbers?