This two-book set with included Hot Dots pen provides children with 100 lessons on a variety of math skills appropriate for preschool, from counting numbers and identifying shapes to math facts and measurement. Plus, the set includes 15 challenge activities that prepare children for skills at the next grade level. Includes two 50-page books, for a total of 100 lessons, plus Hot Dots pen.Details:Includes two 50-page books100 lessons on a variety of math skillsIncludes 15 challenge activitiesRequires 2 AAA batteries (not included)For ages 4 and up