MITxplore will again offer its Sunday Sessions this spring, for 10 weeks beginning February 21, to introduce students in Grades 4-6 to interesting and unusual topics in mathematics not covered in the standard school curriculum. Guided by a Socratic approach, students explore and find solutions on their own. The cost is $150, and financial aid is available. This program fills up quickly so sign up right away. For more information, contact mitxplore-mit@mit.edu or call 617-435-7763. Donations to the MITxplore program are welcome.