Norfolk’s public schools and its Recreation Department  are teaming up to offer a stock market trading simulation program  to children in grades 4 through 6. Students will oversee a virtual cash account  containing $100,000  and work in teams  to make investment decisions to best grow their portfolios over the course of the session. The program begins Feb. 7 and runs for eight classes  through April 11, from 3:20  to 4:30 p.m. each session. The fee to participate is $75. To sign up, visit www.virtualnorfolk.org/rec , register in person in the recreation department office,  or mail a check to Norfolk Recreation, One Liberty Lane, Norfolk, MA 02056. For more information, call the department  at 508-520-1315.