With MC and dpns, cast on 16 (20, 24) sts; divide sts as evenly as possible onto 3 dpns, as follows:
For Children's M, put 5 sts onto the first dpn, 5 sts onto the second dpn and 6 sts onto the third dpn.
For Adult's M, put 7 sts onto the first dpn, 7 sts onto the second dpn and 6 sts onto the third dpn.
For Adult's L, put 8 sts onto each of the three dpn.
Note: When knitting in the round on dpn, your sts do need to be divided fairly evenly onto the needles. If you are working with a set of 4 dpn, your sts should be divided among 3 needles. If you are working with a set of 5 dpn, your sts should be divided among 4 needles. The total number of sts will not always be evenly divisible by the number of dpns that you are using – this is not a problem! Simply divide your sts as evenly as possible, you will still create a symmetrical ‘tube’ of knitting.
Join, taking care not to twist sts. Place marker at beg of rnd. Work in (k 1, p 1) rib for 4 (4, 5) rnds. **With CC, k 1 rnd, then p 3 rnds. With MC, k 2 rnds.** Rep from ** to ** 1 (2, 3) times.
Heel flap (work back and forth)
Cut CC. Turn to WS and with MC, p 8 (10, 12) sts; turn to RS and k 8 (10, 12) sts. (Note Instep sts not being worked can be kept on one dpn.) Rep last 2 rows 1 (2, 3) more times. Turn to WS and p 8 (10, 12) sts.
Turn to (RS) K 4 (5, 6), k2tog, k 1. Turn.
P 2, p2tog, p 1. Turn.
For Child's size only (RS)
K 3, k2tog, turn. For Adult's sizes (RS) K 3, k2tog, k 1. Turn.
For Child's size only (WS)
P 3, p2tog. Turn. For Adult's sizes (WS) P 4, p2tog, p 1. Turn.
For Adult's Large size only (RS)
K 5, k2tog. Turn. (WS) P 5, p2tog. Turn.
K 4 (6, 6) heel sts.
Return now to working in the round, arranging stitches as follows: With dpn #1, pick up and k 6 (8, 10) sts up side of heel flap; with dpn #2, k 8 (10, 12) instep sts; with dpn #3, pick up and k 6 (8, 10) sts along side of heel flap; k across 2 (3, 3) sts of dpn #1 -- 24 (32, 38) sts.
Place marker, on dpn #1, k to last 3 sts, k2tog, k 1; on dpn #2, k across instep sts; on dpn #3, k 1, ssk, k to end of needle. Rep this dec rnd 2 times. K 1 rnd. Rep dec rnd. Rep these last 2 rnds 0 (2, 3) more times (4 [6, 7] dec rnds and 16 [20, 24] sts rem). K every rnd even until Sock is about 2" from desired length to toe measured from bottom of heel flap, ending by working sts on dpn #1 and place marker.
Cut MC. Join CC. K 1 rnd.
Toe dec rnd:
K 1, ssk, k to last 3 sts on dpn #2, k2tog, k 1; on dpn #3, k 1, ssk, k to end; on dpn #1, k to last 3 sts, k2tog, k 1. K 2 rnds even. Rep dec rnd. K 0 (1, 2) rnd(s) even.
For Adults's M & L sizes only
Rep dec rnd.
For Adult's Large size only
K 1 rnd even. Rep dec rnd.
For all sizes
Cut CC, leaving 10" tail. Thread tapestry needle with tail and run through sts rem on needles twice to secure. Draw yarn up tightly and weave in end on inside of Sock. Weave in ends. Make second Sock same.