Either way, they are in high demand and parents often have to pay part of the costs. Activities such as reading, creative writing, sport, computer games, chess, music, dance, foreign languages, and art give an extra intellectual challenge outside of school hours. An umbrella term encompassing myriad educational options for gifted children: part-time schooling; school at home; classes, groups, mentors and tutors; and unschooling. In many US states, the population of gifted students who are being homeschooled is rising quite rapidly, as school districts responding to budgetary issues and standards-based policies are cutting what limited gifted education programs remain in existence, and families seek educational opportunities that are tailored to each child's unique needs  Gifted students are pulled out of a heterogeneous classroom to spend a portion of their time in a gifted class. These programs vary widely, from carefully designed half-day academic programs to a single hour each week of educational challenges. Generally, these programs are ineffective at promoting academic advancement unless the material covered contains extensions and enrichment to the core curriculum. The majority of pull-out programs include an assortment of critical thinking drills, creative exercises, and subjects typically not introduced in standard curricula. Much of the material introduced in gifted pull-out programs deals with the study of logic, and its application to fields ranging from philosophy to mathematics. Students are encouraged to apply these empirical reasoning skills to every aspect of their education both in and outside of class. Self-pacing methods, such as the Montessori Method, use flexible grouping practices to allow children to advance at their own pace. Self-pacing can be beneficial for all children and is not targeted specifically at those identified as gifted or talented, but it can allow children to learn at a highly accelerated rate. Directed Studies are usually based on self-pacing. These offer a variety of courses that mainly take place in the summer. Summer schools are popular in the United States. Entrance fees are required for such programs, and programs typically focus on one subject, or class, for the duration of the camp. Several examples of this type of program are:   Within the United States, in addition to programs designed by the state, some counties also choose to form their own Talented and Gifted Programs. Sometimes this means that an individual county will form its own TAG program; sometimes several counties will come together if not enough gifted students are present in a single county. Generally, a TAG program focuses on a specific age group, particularly the local TAG programs.