DebLuvs and CJ -- it is not a straightforwards multiplication of the 2.5 block measurements. Yikes! Thank you! My method would take a 2.5 in measurement andupsize it to a 5.something square so ultimately it would be much bigger than 26 inches. Time to do some more brain dusting! What a great brain teaser! Double the size of the finished block then add seam allowances. Good thing I have never tried to change the size of a pattern.