To increase several stitches evenly across a row, you must figure out the best spacing for these increases in the same row.
Take the number of stitches to be added and add 1.
This gives you the number of spaces between increases.
Divide the total number of stitches on your needle by the number of spaces between the increases.
For example, if you have 40 stitches and you need to increase 4 stitches, you'll have five 8-stitch sections between the increases. If your pattern calls for you to work bar increases into existing stitches, make your increases in every eighth stitch across the row.
When you’re counting the stitches between increases, don’t include the increased stitches.
If your numbers don’t come out even and you have a remainder of several stitches, you can:
Divvy up the extra stitches and knit them before the first increase and after the last increase.
Alternate working an extra stitch into every other section of stitches between increases until you’ve used up the extras.
Graph paper is great to have on hand for charting out increases — and all other manner of knitting math.