Math help
 

I have 12 star blocks, they measure 8.5 inches. I would like to pair them up with nine patch blocks(sorta like irish chain). When I divide 8.5 by 3, I get 2.83 . What size strips would that be in inches.

Your 8.5 inch blocks will finish to 8 inches, so what if you did 16 patches instead of 9 patches? Then you'd use 2.5 inch squares, which would finish to 2 inches.

You need to remember that the 9 patch needs seam allowance in it. So you need 3 3/16 strips to make the 9 patch. That gives you 9 9/16 of fabric wide that will end up at 8 9/16 after the seams. It will be a tiny bit larger than the star but close enough.

ljfox you are very good at calculating

Thank you so much for figuring this out. A tiny bit bigger is doable. These blocks are leftovers from another project, otherwise they sure would have been 9 inches.
These stars are an assortment purples & whites. My nine patches are going to be maybe pink & white or should I use some other colour.

Just to check - you do mean that the block is 8.5" unfinished and will finish to 8"?

Ditto the question.

I'd probably make the 9 patch to finish at 6" and then put a 1" border around it to make it 8" finished.

Yes 8.5 finishing at 8.

8 / 3 = 2.6666 or 2 2/3 which is very close to 2 11/16 (2.6875)

So, for a 2 11/16 finished square, when you add in your seam allowance of 1/4 inch each side, the cut squares should be 3 3/16 inch squares