For the black quilt block, it's a "slice and dice" method--you sew, then cut, then sew together a bit differently.
Sew the red strips with two black strips, cut into three pieces and add the remaining black strips.
The chop and sew method is the one on the left. It's okay, but it's not nearly as accurate as the one on the right, which is foundation pieced. The paper stabilizes the fabric and allows you to sew perfectly straight seams, and when you are working with 3/8 inch finished strips of fabric, you need all the help you can get. Okay, point made and re-learned!