Stitches don't add up if I follow the pattern
I am knitting a baby beanie, cast on 90 stitches, the body is knitted in moss stitch, about to shape the crown in the following pattern, but the decrease doesn't add up:
*pattern 7 stitches, slip 1, knit 2 together, pass slipped stitch over, rep from * to end. 81 stitches.
However, I feel like thay produces a double decrease in which case I am only left with 72 stitches? Is the pattern wrong or am I misinterpreting it?