I'm not very good at math, but thought I would give it a try to help you. I was multiplying the size of the block x the number of blocks and you can't get there. 8x9=72. 9x9=81. I think you are going to have to change the dimensions of your quilt so that the finished size of your block is an even equation. You can make 9 eight inch blocks (finished) for a dimension of 72 inches and then put your 2 inch border on or make it a wider border. Since that is only 2 inches smaller than what you have described, it might work for you. I hope this gives you a starting point. Good luck. Gina