3.1 Natural numbers
While there are special and famous numbers such as π, the numbers we use for counting are much simpler: 1, 2, 3, … . I might say, “Look, there is 1 puppy, 2 kittens, 3 cars, and 4 apples.” If you give me 2 more apples, I will have 6. If I give my sister 1 of them, I will have 5. If I buy 2 more bags of 5 apples, I will have 15 in total, which is 3 × 5.” natural number number$natural
The set of natural numbers is the collection of increasing values
where we get from one number to the next by adding 1. 0 is not included. The braces “{“ and “}” indicate we are talking about the entire set of these numbers.
When we want to refer to some arbitrary natural number but not any particular one specifically, we use a variable name such as n or m.
The set of natural numbers is infinite. Suppose otherwise and that some specific number n is the largest natural number...
