Two Sided Provisional Cast On
Crochet a chain with a smooth scrap yarn (for instance cotton) in a contrasting color. Chain a few more stitches than you will be casting on.
To the right you see the back of the chain with the bumps.
Right side; at the end of the sleeve round pick up and knit the number of stitches given from the chains back bumps.
Wrong side; turn your work and purl the new sts. Continue purling the sleeve stitches. At the end of the row, let go of your right hand needle and the working yarn.
With a spare needle that is preferably smaller than your working needle, pick up the stitches you have just cast on. Start at the edge of the chain and work towards the underarm. Do not pick up from the crochet chain, but instead pick up the purl bumps of the main yarn.
Change direction again, the needle you have picked up stitches with, becomes your left hand needle and the needle you’ve just purled the sleeve stitches with, your right hand needle. With the right hand needle purl the stitches you’ve just picked up from the chain.
This is the wrong side after working Step 1 to 5.
Turn your work and knit to end using Magic Loop to round the corners.
This is the right side after working one knit row.
Unpick the crochet chain.
You are now ready to work the front and the back of your sweater as one piece. Close the holes at the underarms when you finish your sweater.