Reading a pattern

question on part of a pattern instruction
Doing the sleeve in a baby cardigan
Pattern says
Make 2 both same (understand)
Cast on 35 stitches and work 10 rows in garter stitch.
(Did this 10 rows done)
Next says
Inc at each end every 4th row until I have 55sts
Work straight until sleeve measures 6 inches. None off loosely.
SO this means knit 3 rows. Then 4th row increase a stitch at beginning and end.
Knit 3 more rows which have 7 rows now. The 8th row increase stitch at begin and end. Continue doing this till have 55 sets. IS THIS CORRECT?

That’s right, you work 3 rows then increase, repeat until you have 55 stitches. After that continue without increases until piece measures 6”.