CO 40 with long tail tubular cast on.
1/1 rib for 17 rnds
Sl1, p1 around
Knit 5 rnds
2sts between marker; M1L, knit to marker, M1R
Alternate increase rnds with knit rnds for 14 rnds, ending w/ knit rnd (16 sts for thumb)
Knit 6 rnds
CO 2, join and knit
Knit 1 rnd, insert waste yarn
Sl1, p1 around
1/1 ribbing for 37 rnds
Kitchener BO

Thumb:
Pick up 2 sts
Knit 3 rnds, decreasing at corners (16 sts) on first rnd
Sl1, k1
1/1 rib for 7 rnds (including sl rnd)
BO