I was just calculating this this morning and drove myself crazy. Finally I found an explanation (In Quilter's Cache):
To make four at a time, cut a square 1 1/4" larger the the size you want your rectangle to be and four small squares 7/8" larger.
Example: for a 4 x 2 flying geese, cut the square 5 1/4 and the small squares (4 pieces) 2 7/8"