Advice when doing any block any method the first time. Do one block to make sure you understand all the instructions. Then do 2 or 3 to make sure your chain piecing is accurate and you understand the process. Then and only then, cut more and chain piece a bunch together.
This is from experience. The pattern could be wrong or you could make one bad mistake and, if you have not tested first, you can waste a lot of material and time.