I vote that you let them get as far as they possibly can. For example, I am a third grade teacher and 23 out of 25 kids in my class have completed super speed 1000 successfully. I started doing super speed at the beginning of the year with 100 and the kids feel in love with it. I vote you not put a cap on their words but a quota that they must meet. I would challenge your students to finish 100 and go beyond. I hope this helps....I love superspeed and have seen the magic happen in my classroom this year. I had 8 students in my class who could not read at the beginning of this school year. Now, I have 25 students who enjoy reading and continue to amaze me with their skills.