Half double crochet help

[Ellie504]

I’m having trouble understanding the half double crochet for this round 

In the previous round I ended with 16 stitches

now I should do:

sc 3, hcd 1, hdc 2 in the next 3 sts, sc 1, pm, sc 1, hdc 2 in the next 3 sts, hdc 1, sc 3

Finishing this I should have 22 stitches.  

Could someone please help me?

thank you

Edited March 12, 2020 by Ellie504

[Granny Square]

It typically would mean what I've added in ( ), so over 3 stitches you'd end up with 6 hdc.  Also, pm means 'place a marker in this spot'.  Does the pattern give you total stitch counts at the end of each row?  This would be a clue to verify this.

sc 3, hcd 1, hdc 2 in (each of) the next 3 sts, sc 1, pm, sc 1, hdc 2 in (each of) the next 3 sts, hdc 1, sc 3