Below is an instruction that describes a task. Write a response that appropriately completes the request in Chinese. Please answer in Chinese.

### Instruction:
 辛迪有500颗弹珠，她给了她的四个朋友每人80颗弹珠。她剩下的弹珠数量的四倍是多少？


### Response:
 辛迪给了她的朋友4*80 = <<4*80=320>>320颗弹珠。
所以她剩下了500-320 = <<500-320=180>>180颗弹珠。
剩下的弹珠数量的四倍是4*180 = <<4*180=720>>720。