Numbers Ending With...

To list numbers with the same end digits, it is possible to browse all the integers in ascending order and check their last digits. Another faster method is to browse these same integers and to concatenate the final digit(s) to it.

Example: 5, 15, 25, 35 are the first numbers ending with 5 (and therefore all numbers are multiples of 5)

Some digits positioned at the end of the number make it possible to deduce that the number is a multiple of N (under some conditions).

Example: A number ending in 00 is necessarily multiple of 100 (but also 50, 25, 10, 5, and 2)

Example: A number ending in 5 is necessarily multiple of 5

Example: A number ending in 0, 2, 4, 6 or 8 is necessarily multiple of 2

Numbers that end with one or more 0 are multiples of 10, sometimes called round numbers.

Mathematically speaking, a round number is different, it is an integer that does not have a point and decimal digits, only an integer part.

An automorphic number is a natural integer $ n $ whose squared value $ n^2 $ ends with the same digits as the number itself.

Example: 76^2 = 5776

Example: 625^2 = 390625