If an integer ends with an 1.

If you divide an integer by 10 the result will be the number of "10s" that exist within your value, but there may be some left over - the remainder. The remainder can be between 0 and 9. It will be 0 if the integer is evenly divisible by 10. As it turns out it will be 1 if the integer ends in a 1.

The modulus operator gives you the remainder after dividing one value by another, so you can use that operator to easily check if the remainder is 1...

 if (value % 10 == 1)
 {
     Debug.Log(value);
 }