By Amy Harris
Updated Aug 30, 2022
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In mathematics, the successor of a number is the next whole number, while the predecessor is the one immediately before it. To find the successor of a given whole number, simply add one. To locate its predecessor, subtract one.
• If the starting number is 18, its successor is 19 and its predecessor is 17.
• For 226, the successor is 227 and the predecessor is 225.
Note: Whenever x is the successor of y, y is automatically the predecessor of x. For instance, 80 follows 79, so 79 precedes 80.
The concepts of successor and predecessor apply exclusively to whole numbers—zero, one, two, three, and so forth. They do not extend to fractions, decimals, or negative values.
Every whole number has a successor. With the exception of zero, each also has a predecessor. This foundational rule underpins many areas of number theory and discrete mathematics.
