21 yuan. Shengdao points is a membership points system introduced by YYsports Shengdao Sports Store. By participating in activities such as running and punching cards, members can earn points and deduct cash or exchange designated goods when spending in stores. The minimum redemption unit of points is 511 points, and every 511 points can be deducted by 11 yuan. Therefore, 1111 points of Shengdao can reach 21 yuan.