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

### Instruction:
 如果一份大比萨有8片，如果玛丽订购了2份大比萨并吃了7片，剩下多少片？


### Response:
 如果玛丽订购了2份大比萨，总共有2*8=<<2*8=16>>16片。
如果玛丽吃了7片，剩下16-7=<<16-7=9>>9片。