OK, I am really math challenged this morning. If anyone could help I would be so grateful.
My center that I am working on is 64 1/2 inches square. I am wanting to add a narrow border to that and then add another border that measures 6 1/2 inches unfinished squares.

How wide a border do I need to add to the existing center for the 6 1/2 inch border to work out evenly? I have been drawing this and trying to figure it out all morning. Guess I need more coffee!

Thanks for any help.

If I understand your problem, you would add a 2-1/2" strip to your center. That should make your center 66-1/2" square, which will finish down to 66" square. That way, you can put 11 squares of 6" (finished size) along each side. If you do two opposite sides first, then you would need 11 blocks on each, and 13 blocks on each of the other two sides (i.e., if you don't you'll have "holes" at the corners).

HTH,

Odessa

The center now measures 64 1/2 inches - I have a bunch of 6 1/2 inch (unfinished ) squares that I want to use as the last border. I need to add a narrow border all the way around the 64 1/2 " center to make this work. If I add 2 1/2 inch border all the way around wouldn't I then have 67 1/2 inch center? Oh, you can see why I am having so much trouble - I just can't figure this out today.

If you can't figure it out, I would just start sewing my squares together. When they are the length you want them, then I would figure out what size border I need before attaching them. I am very visual and this would be much easier if I were doing it.

64 1/2 + 2 1/2 = 67 - 1/2 (seam allowances) = 66 1/2 square

Thank you all so much!!! Could never figure out the train thing either... If a train is travelling east at 65 MPH...............LOL

It travels the distance of one mile in 55 seconds. LOL

my dream while I am still alive is know the formula for the train and its speed.

perhaps part of your difficulty is looking at the unfinished size of the center. It will finish at 64"
11 of your 6" (finished squares) will be 66" The difference is 2" finished inner border. So the posts above are correct in suggesting 2 1/2 inch cut strip for your inner border. Be sure you measure the center down the center to make sure it is square so the inner border will keep it in the square.

Thank you all, had to go out (which was probably a good thing) and now I will give this a go.

Thank you all for your help.