How to Decrease Single Crochet
You can decrease a stitch (abbreviated dec), which is really just subtracting a stitch, in a single crochet row. You decrease stitches in single crochet in the same places that you increase stitches — at the ends of the row or somewhere in the middle:
1Insert your hook into the next stitch.
If you’re decreasing at the beginning of the row, insert your hook in the first stitch.
2Yarn over (yo) and draw the yarn through the stitch.
You should have 2 loops remaining on your hook.
4Yarn over (yo) and draw the yarn through the stitch.
You should have 3 loops on your hook.
5Yarn over and draw the yarn through all 3 loops on your hook.
You’ve completed one single crochet stitch decrease.