A more thorough explanation:

Definition: Half plus one is a common but not always accurate way of approximating a majority. For example, in a group of 100 people, a majority would be 51 people. However, if the group has an odd number of members, half plus one would not be a whole number. Therefore, it is better to use the term "simple majority" to indicate majority rule. Another term for this is 50 percent plus one.

Example: In a class of 25 students, half of the students would be 12.5. Since we cannot have half a student, we would round up to 13. Therefore, a simple majority in this class would be 14 students (half plus one).

Explanation: This example illustrates how half plus one can be an inaccurate way of determining a majority when dealing with odd numbers. In this case, a simple majority of 14 students would be needed to make a decision.