According to the analysis of "reducing the number A to one tenth of the original number is equal to the number B", it shows that the number A is 10 times of the number B, and from the meaning of the question, the number B is (10+ 1) times of 253. According to the known multiple of a number, the number can be found, and then the number b can be found by division.

Solution:

Number B:253( 10+ 1)

=253÷ 1 1

=23

A number: 23x 10=230 (or: 253-23 = 230)

A: The number A is 230.