Sock Gusset Increases Help

[whitneyg]

I am having trouble understanding the gusset increases portion of a top down flap-less sock heel. The pattern reads:

"Increase rnd: M1R, PM, K0(3,6,9) work chart to end, k0(3,6,9), PM, M1L.
Work 2 rnds even.
Increase rnd: M1R, k to marker, SLM, K0(3,6,9) work chart to end, K0(3,6,9), PM, M1L, SLM, k to end, M1L.
Work 2 rnds even.
Repeat these three rnds 7 more times, knitting all newly created sts in MC and being sure to catch the CC every few sts. On the last even round, work only to the second marker, leaving the 9 newly created sts unworked. 90 (96, 102, 108) sts."

The thing I'm hung up on is that I don't see how you will have a total of 18 extra stitches after adding 2 and then 3 repeated 7 times. Am I correct in reading that in the second increase round 3 additional stitches are added, M1R, M1L, and then M1L at the end?

Also, I'm assuming that the 3 rounds to be repeated is the second increase round and the following 2 worked rnds. Does that sound right?

I've tried a few times on some quick dummy socks and I just can't get it to work out.

Thank you!

[salmonmac]

You're right that the 3 rounds to be repeated are the 2nd increase round and the following 2 even rounds. I'm not sure why you say 18 extra sts? I see "9 newly created sts" mentioned in the pattern after the 2nd marker. That's created by the first increase round, the 2nd increase round and the 7 repeats (9sts increased after the 2nd marker).
Total number of increases is 26 (2sts in first inc rnd, 3sts in 2nd inc rnd, 3x7 in following repeats).

[whitneyg]

Yes! I guess I wasn't paying attention to the use of the second marker enough. I will try this out.
Thank you!