The way this pattern is written is really confusing. At first I thought the numbers were all wrong, but after puzzling through it and tracking the number of stitches at each row, I think there are three mistakes.

1. In the collar, I think the stripes should be in ridges, not rows. The image shows them being about the same as the hem, which is given in ridges, and the color changes would look weird if they were in rows instead of ridges.
2. 640 doesn’t sound right for the number of stitches to pick up along the hem since it says to pick up a stitch for every ridge and one for in between each ridge, which would make you have more them 640 stitches.
3. The book doesn’t define half-stitch in its list of crochet stitches so I think they mean half-double, which is defined.

I didn’t like how ruffled the striped section at the hem looked in the pattern image so I only picked up three stitches for every four rows along the bottom instead of four.