FTCE General Knowledge Math Practice Test

What defines natural numbers?

1. All positive numbers including zero

2. Positive counting numbers

3. All integers

4. Negative and positive numbers

The correct answer is: Positive counting numbers

Natural numbers are defined as the set of positive counting numbers. This includes numbers like 1, 2, 3, and so on, which are used for counting and ordering. The concept of natural numbers does not include zero or any negative numbers, which differentiates them from other sets of numbers. While the choice that includes all positive numbers including zero may sound accurate, traditionally, natural numbers start from 1 and not from 0. The other options encompass broader categories of numbers: all integers include both positive and negative whole numbers, while the entry for negative and positive numbers refers to the entire set of integers, which are not confined to just the natural numbers. Thus, the definition of natural numbers is correctly represented by positive counting numbers, as they serve a fundamental role in basic arithmetic and number theory.