How to set 1st number in row = 10, and increment by 10 every time Button to Add new row is pressed. Also allow users to enter generic numbers, i.e 13 and still increment by 10 to be 23 or whatever.

How to set 1st number in row = 10, and increment by 10 every time Button to Add new row is pressed. Also allow users to enter generic numbers, i.e 13 and still increment by 10 to be 23 or whatever.

I already have my table set up with a Button that will add new rows when pressed.

I now want to specify that the 1st row is 10 and any other rows after that increment by 10. This will also allow users to enter any number they'd like and the next row will increment by 10.

Help please.