Dividing 31/2 into a 44 wide fabric will yield approximately 12 pieces per 31/2 strip. Using this converter, that would require 1/9 of a yard. If we want 100 pieces, divide 100 by 12 which will equal 8.3 strips. Round up to 9 strips. 9 strips times 3 1 / 2 equals 31.5. Round up to next chart entry, 32 which is 8/9 of a yard. We would probably need to buy one yard. I don't know of a fabric shop which measures that minutely when cutting fabric, but I trust you get the idea. Thanks to Campbell atAOL for the inspiration to add this.