Hong Hong went to the supermarket to buy chocolates, and the salesperson aunt said: "8 pieces of chocolate cost 7 yuan". Honghong has 21 yuan now, how many pieces of chocolate can she buy?
红红去超市买巧克力，售货员阿姨说："8块巧克力7元钱"．红红现在有21元钱，可以买几块巧克力？
<result>8</result>