Can't resolve extra sticthes

Hello - This pattern does not work out mathematically to me; if I follow Row 1, I have 4 stitches left over?

171 stiches
K5, *Sl1P. K5. Rep from * to end of row.

Can someone point out what I am doing wrong?

Here is the pattern

Welcome to KH. If you look on this Ravelry page Mary1128 says changing the last row of garter stitch to 6 increases instead of 10 made it work. I think that should fix it for you, my calculator agrees with Mary1128’s change. HTH