Directions dilemma

The pattern is Radiant Rainbow. I’m at the border.
It reads,”With RS facing, pick up and knit 1 stitch for every ridge along long edge of rectangle; count stitches and adjust to a multiple of 4+6 on next row. Work 3 rows in stockinette.”
I don’t understand adjust to a multiple of 4+6 on the next row.
Can someone help please?

You want the total number of sts picked up to be a multiple of 4 like 20, 24, 40, 48, some number divisible by 4. Then add 6 to that number. So 20 + 6, 24 + 6, 40 + 6, or 48 + 6. That’ll be the goal for picked up sts.
The easiest thing to do is to pick up the sts, one for every ridge along the long edge of the rectangle and then figure out what the closest correct number would be. On the next row add a stitch or 2 or work sts together to get to the desired multiple.

Thank you so much for your clearly stated explanation.