Here's another free pattern for you. Quick and easy, I whipped them up in a few hours for my friend's little boy. They would be easy to make bigger or smaller too, just add or decrease stitches in multiples of 4 (remember to adjust the thumb gusset accordingly). This pair fits approximately ages 4 to 7, there's a lot of stretch in them. And they look hideous when there are no hands in them! Just so as you know, and don't freak out while you're making them.
You will need:
2.5mm circular needles
Approximately 30gm fingering weight yarn
2 small safety pins to use as stitch-holders
2 stitch markers if required.
Cast on 48 sts and join for knitting in the round, 24sts on each needle.
K2, P2 rib for 3.5 inches.
On the next round, kfb, k1, continue knitting in rib to end of round.
On each round now, you will increase 2 sts to create the thumb gusset. So the next round will be kfb, kfb, *p2, k2* to last 2 sts, p2.
Next round: Kfb, k2, kfb, *p2, k2* to last 2 sts, p2.
Next round: Kfb, k4, kfb, *p2, k2* to last 2 sts, p2.
Continue increasing in this manner until you have an extra 18 sts, then on the next round, knit those extra sts and place half each on a small safety pin and forget about them for now.
K2, P2 rib on the remaining sts (you should still have 48 active sts) for another 2.75 inches.
Cast off knitwise.
Now you'll need to put those thumb gusset sts back on your needles, 9 sts on each. Knit one round, picking up 2 sts from where the body of the mitt joins the thumb. This will help to close any gaps, and means that you now have 20sts on your needles. For the next 7 rounds, *k2, p2* around, then cast off knitwise.
Work in ends.
As always, if anything doesn't make sense or is unclear, let me know! And again, as always, feel free to use the pattern to make gifts, or to sell the mitts, but please link back to my blog and credit me as the pattern designer.