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

### Instruction:
 艾萨克把他的30米长的丝带切成了6等份。然后他用了4份丝带。还有多少米的丝带没有用？


### Response:
 每份丝带是30/6 = <<30/6=5>>5米长。
由于艾萨克用了4份，所以他用了5 x 4 = <<4*5=20>>20米的丝带。
所以，还有30 - 20 = <<30-20=10>>10米的丝带没有用。