Kumon Answer Book Level B Math -
Yes. In Kumon pedagogy, Level B is where students either develop "automaticity" (the ability to recall math facts instantly) or they crash. Students who cheat through Level B using an answer book invariably fail Level C (multiplication) because they cannot add quickly.
If your student is spending more than 30 minutes on a Level B worksheet (standard time is 10-15 minutes), do not reach for the answer key to speed them up. Instead: kumon answer book level b math