Fuzzy Math??

Hi,
I just started a new (to me) pattern and am already confused. The very first lines says the following, exactly:

Chain 149
Row 1 (Right Side) Dc in 4th ch from hook and in each ch across, turn - 147 sts,

If I have 149 chains, and dc in each chain, starting in the 4th chain, how do I end up with 147 stitches?? Wouldn't it be 146? It doesn't tell me to chain 3 until the beginning of the next line after the turn.

What am I not getting? I've seen lots of pictures of this blanket, finished, so I know the directions have been tested . . . ????:confused: