FTCE Professional Education Practice Exam

Natural numbers are defined as which of the following?

1. All real numbers

2. Negative integers starting from -1

3. Counting numbers starting from one

4. All even numbers only

The correct answer is: Counting numbers starting from one

Natural numbers are defined as counting numbers starting from one. This includes the set of positive integers: 1, 2, 3, and so forth. Natural numbers are fundamental in mathematics as they are used for counting objects and ordering them. The reason this definition makes sense is that natural numbers form the basis of our understanding of quantity and order in everyday scenarios, such as counting apples, people, or any discrete items. They are essential for arithmetic operations, and their properties are extensively studied in number theory. The other options do not accurately reflect the definition of natural numbers. All real numbers encompass a much broader range, including rational and irrational numbers, positive and negative numbers, which goes beyond the concept of natural numbers. Negative integers, as described in one of the options, do not qualify as they are not part of the natural number set. Lastly, stating only even numbers as the option limits the definition further, as natural numbers include both odd and even counting numbers.