I purchased this for my 7 year old who is in second grade (homeschool). He really loves the workbook and wants to do all the activities for the week in one sitting. The words are not too hard. I can easily see him finishing and moving on to the third grade level before finishing second grade.
Each week has a spelling tip/rule which the words fall under. For those who would like to know. . . the words in the first lesson are fox, cut hill, wind, put, all moon, saw, tell, new (which seem very easy for 2nd grade). Week thirty-five's words are hole, whole, no, know, not, knot, ate eight, to, too, two, right, write, one, won. I think our local public schools did these type of words in 1st grade. My son did not have "formal" spelling last year so I don't mind starting him off with easier words. I've found it is better to start easy and build confidence than to ruin a child's self-esteem with something too hard. I do believe; however, that if your child has already had formal spelling it would be easy to move on to level C and skip level B.
I have tried many spelling programs over the years (with my oldest son) and my children rate this one as the best. It has interesting activities such as crossword puzzles, find the missing letters, proofreading, etc. My favorite part is that each week the child has a short story to read that uses all of the week's spelling words. The stories are usually educational too! If your child enjoys short activities to reinforce what he/she is learning, I believe you will find this program a perfect fit.