The pattern for this blanket has an odd number of rows which makes it reversible. Once you get going you will see how easy it is - as long as you keep track of your stitch counting (try BeeCount app on your phone)

There may be an error which is detailed below but will be confirmed once this editor has finished it:

It say to cast on 122 to allow the rib to end with k2 but the pattern is in 9 groups of 12 plus 12 stitches of rib which is 120 so you will need to, on row 7, rib 6 then dec 1. pattern to the last 7 dec 1, rib 6. On the row where you change to the smaller needle for the final 6 rows of rib increase one each end at the same place - after and before the first/last 6 ribs.