There’s a common belief about the mental acuity of the aging brain: "If you don’t use it, you lose it.” Research published in the December 20, 2006 issue of the Journal of American Medicine confirms it: "If we challenge our minds...it does in fact improve memory and this improvement can be sustained.” That’s why AARP has teamed up with puzzle expert Frank Longo to present this collection of sudoku puzzles guaranteed to provide a solid workout for brain cells that have been around the block. The puzzles, ranging from easy to medium in difficulty, offer a healthy dose of fun along with all the benefits of mental fitness. Solvers will reap the rewards of exercising concentration, care, and logic.