First, thanks for checking out my sudoku! Let me explain the rules a little better. The numbers outside the grid represent the sum of the digits located between the digits 1 and 9 in that row or column. For instance, a 0 indicates that the 1 and the 9 in that row or column are adjacent to one another, while a 7 indicated that the digits between the 1 and the 9 in that column sum to 7 (whether that is a single 7, the numbers 2 and 5, or the numbers 3 and 4 is for you to figure out!). Here's a video explaining that a bit more if you need it: https://www.youtube.com/watch?time_continue=188&v=zKL6vgVtYss&feature=emb_logo