# Successor and Predecessor

The successor and predecessor of a whole number are discussed below:

SUCCESSOR

The number which comes immediately after a particular number is called its successor.

The successor of a whole number is the number obtained by adding 1 to it.

Clearly, the successor of 0 is 1; successor of 1 is 2; successor of 2 is 3 and so on.

We observe that every whole number has its successor.

PREDECESSOR

The number which comes just before a particular number is called its predecessor.

The predecessor of a whole number is one less than the given number.

Clearly, the predecessor of 1 is 0; predecessor of 2 is 1; predecessor of 3 is 2 and so on.

The whole number 0 does not have any predecessor.

We observe that every whole number, other than zero, has its predecessor.

Also, if a is the successor of b, then b is the predecessor of a.

For example:

Find the successor and predecessor of each of the following whole numbers:

(i) 1000

(ii) 11999

(iii) 400099

(iv) 1000001

(v) 99999

Solution:

(i) 1000

The successor of 1000 is (1000 + 1) = 1001.

The predecessor of 1000 is (1000 - 1) = 999.

(ii) 11999

The successor of 11999 is (11999 + 1) = 12000.

The predecessor of 11999 is (11999 - 1) = 11998.

(iii) 400099

The successor of 400099 is (400099 + 1) = 400100.

The predecessor of 400099 is (400099 - 1) = 400098.

(iv) 1000001

The successor of 1000001 is (1000001 + 1) = 1000002.

The predecessor of 1000001 is (1000001 - 1) = 1000000.

(v) 99999

The successor of 99999 is (99999 + 1) = 100000.

The predecessor of 99999 is (99999 - 1) = 99998.

What is Successor and Predecessor of a number?

The Successor and Predecessor of a number are explained using examples.

PREDECESSOR                NUMBER                SUCCESSOR

(7148 - 1) 7147                 7148                  (7148 + 1) 7149

(8950 - 1) 8949                 8950                  (8950 + 1) 8951

(7620 - 1) 7619                 7620                  (7620 + 1) 7621

(12499 - 1) 12498              12499                 (12499 + 1) 12500

To find the predecessor of a number, subtract 1 from the given number.

To find the successor of a number add 1 to the given number.

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