Which set does NOT include zero?

Which set does NOT include zero?

• A. Natural numbers
• B. Whole numbers
• C. Integers
• D. Real numbers

Answer: (A)

The main idea is how these number sets are defined and whether they include zero. Zero is part of integers, real numbers, and the set of whole numbers (0, 1, 2, ...). The set of natural numbers, however, is often defined as the positive integers starting at 1 (1, 2, 3, ...), which means it does not include zero. Therefore, under this common convention, the natural numbers are the only set that does not contain zero. Note that some texts define natural numbers to include zero, in which case the answer could differ.

The main idea is how these number sets are defined and whether they include zero. Zero is part of integers, real numbers, and the set of whole numbers (0, 1, 2, ...). The set of natural numbers, however, is often defined as the positive integers starting at 1 (1, 2, 3, ...), which means it does not include zero. Therefore, under this common convention, the natural numbers are the only set that does not contain zero. Note that some texts define natural numbers to include zero, in which case the answer could differ.