On the last day of A.D. 2023 my friend W.G. asked me to provide a 4 digit number, which after erasing its second digit (from the left) becomes 1/7 of its original value.
No big deal, I did it on the spot, but in return told him that this number can be defined by some other features and then we have jointly agreed upon at least 2 short descriptions.

I leave it to you :

1. To find the number
2. To provide some not-too-long definitions

The number is 1050=7*150. However, it is more interesting that you mentioned the last day of 2023, which is 123123.

Posted by Math Man on 2024-01-05 16:12:42