Round 4: [inc, 4 sc] x 3 (18)
Round 5: 18 sc (18)
Round 6: ch 10, sl st into the ninth stitch of the previous round (11)
There's quite a few new abbreviations in that last round, but don't worry - be hoppy! These stitches are simple and a great addition to your crochet stitch tool chest.
First, watch this video to learn how to crochet a chain stitch:
Then slip stitch into the ninth stitch from where the chain started from:
To finish, invisible fasten off: