Hello I’m new to this forum amd really hope someone can help!

I’ve got to the sleeve on this jumper and I’m struggling to understand the instructions:

Inc twice 1 st every 10 rows, 4 times 1 st every 12

rows.

I get it wants me to increase 1st on either side every 10 rows but it doesn’t make sense and I dont get the second bit!?

I’m knitting the medium sweater and looking at how many stitches I’d have left after the increase by my math if end up with a lot more than I should of inc 2 stitches one at either end.

Help?? I’m so confused x

Thank you

Suzie Lou