Heat oven to 425°F. On lightly floured work surface, unroll 1 pie crust. Roll to 12-inch circle with rolling pin. With 6-inch round cutter, cut 2 rounds from crust. Reroll scraps, and cut 1 additional round. Repeat with remaining 5 pie crusts, for a total of 18 pie crust rounds. Place 9 rounds on lightly floured cookie sheets. Cover with plastic wrap; refrigerate until needed for top crusts. Fit remaining 9 rounds in bottoms and up sides of 9 ungreased tart pans, pressing firmly. With fork, prick bottoms and sides generously. Place tart pans on ungreased cookie sheets.