Divide the total number of stitches in the sweater by the number of stitches you need, which is the interval number. Just divide them equally.

The number of stems should be odd, either centered on the center of the front and back pieces or centered on the shoulders, so as to be symmetrical and beautiful.

The number of needle intervals depends on how much fat you need. If you are fat, you will have fewer intervals, and vice versa.

Needle adding method: you can pull a needle up; You can also choose two stitches from one stitch in the previous trip. The latter is generally used, and it looks better without pinholes.