335 yards of worsted weight yarn of your choice. Check the yardage measurement on the ball of yarn to make sure you are purchasing enough; you may need to purchase two or even three balls, if they are sold in shorter yardage amounts. Whichever yarn you choose, the baby’s parent(s) will likely be grateful if the garment can be thrown in the washer and dryer.
I- 9/5.5 mm hook Four buttons, 1/2”
A yarn or tapestry needle, for sewing up
Coilless safety pins or locking stitch markers (you’ll understand when the sweater gets sewn up)
Construction
Back
Foundation Row (FR): Chain 27 stitches
Next: single crochet in 2nd chain from the hook, sc in each chain stitch to end. You should have 26 sts; turn work.
Next: ch 1, sc in each st to end—26 sts; turn work.
Repeat last row until the piece measures 8” high and fasten off.
Fronts - Make 2 of these! FR: Chain 14 stitches.
Next: Single crochet in 2nd chain from the hook, sc in each chain stitch to the end. You should have 13 sts. Turn your work.
Next: Chain 1, sc in each stitch to the end. You should still have 13 sts. Turn work.
Repeat the previous row until the piece measures 8” long. Fasten off and set aside.
You’re getting there! Now make the other front, following the same instructions. You’ve got this!
Sleeves - Make 2 of these as well!
FR: Chain 22 stitches.
Next: 1 single crochet in 2nd chain from hook, sc in each chain st to the end. You should have 20 stitches. Turn your work.
Next: Chain 1, sc in each st to end. There should be 20 stitches. Turn the work.
Repeat the previous row until the piece measures 6-¾” high. Fasten off and set aside.
Assembly:
To put all your pieces together, you’ll sew the front and back shoulder seams together first. Then the upper arms get sewn to the shoulder seams. Here’s how we’ll do that.
The front and back pieces were made from the bottom up, so the chain edge is your bottom of all pieces. Lay the back and one of the front pieces together, “right” sides together. (The beauty of single crochet is that it has no “right” or “wrong” side, so it doesn’t matter which face you show to the  world!)  Thread your tapestry needle with about 10” of yarn and beginning at the sleeve end of one shoulder, whip stitch across to about an inch away from the neck opening. Repeat on the other side of the back with the other front piece.
Now we’ll sew the sleeves on.
Your chain edge on the sleeves is the cuff hem, and where you fastened off is the shoulder. Fold the sleeve in half. The side that is currently facing out will eventually become the inside of the sleeve. Now take the sleeve and center the fold at the top of the sleeve on one side of the garment. Half of the sleeve top will be sewn to the back and half to the front. Pin these pieces together with the coilless safety pins (or locking stitch markers) that I mentioned in the materials list.
Now thread your tapestry needle with about 15” of yarn. Whip stitch the top of the sleeve to the body pieces. Repeat on the other side of the sweater with the other sleeve.
Next we’ll sew up the sides. All your pieces should be “inside out,” or “wrong side out.” Thread your needle once more with approximately 20” of yarn and whip stitch the side of the sweater (the back and one front piece) from hem to armpit, then continue sewing the two sleeve edges together from armpit to wrist.
Tip - If you find 20” of yarn too much, not to worry! Use half that length. But if you choose this route, sew from the armpit to the hem, then down the sleeve from underarm to cuff.