I usually love using Kumon workbooks in my son's homeschool curriculum, but this one was a slight disappointment. There are four types of exercises: tracing numbers, fill in missing numbers in sequence, circle specific numbers (identification), and dot-to-dots. The repetition helps retention, but I had a few issues with the set-up.
1) In some of the sequence exercises, there are two rows of numbers, but some numbers have been skipped at the end or beginning of each row, so it's not a complete number sequence. I don't know how skipping numbers is suppose to help learn to count properly.
2) The dot-to-dots come in three sizes: large font with visible pathways, medium font, and a tiny font that might be hard for some kids to focus on. Some of the patterns were a little more complex than what I expected for 4-6 year olds. Also, my left-handed child couldn't always see the numbers he was looking for, especially with the tiny font.
3) Kumon workbooks are bound pretty tightly, and they are not perforated, so I usually have to hold the workbooks open for my son. This was difficult with some pages that were written horizontally; my son had to stretch across one page just to write on the adjoining page.
While my son does know how to count to 120 now, both my son and I were grateful to be done with it.
I would recommend just using Numbers 1-100 Flash Cards or the Number Cheap Chart 1-100, since there wasn't any computation in this workbook anyway.