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

### Instruction:
 莎莉星期一缝了4件衬衫，星期二缝了3件衬衫，星期三缝了2件衬衫。每件衬衫有5个纽扣。莎莉需要缝多少个纽扣才能完成所有的衬衫？


### Response:
 莎莉一共缝了4 + 3 + 2 = <<4+3+2=9>>9件衬衫。
她需要的纽扣总数是9 x 5 = <<9*5=45>>45个纽扣。