solution: A terminating decimal can be written in the form $\frac{a}{10^b}$, where $a$ and $b$ are integers. So we try to get a denominator of the form $10^b$: $$\frac{21}{2^2\cdot5^7}\cdot\frac{2^5}{2^5}=\frac{21\cdot32}{10^7}=\frac{672}{10^7}=\boxed{.0000672}.$$
prompt.content: <|im_start|>system
  You are a helpful assistant.<|im_end|>
  <|im_start|>user
  Convert $\frac{21}{2^2 \cdot 5^7}$ to a terminating decimal.
  Please reason step by step, and put your final answer within \boxed{{}}.<|im_end|>
  <|im_start|>assistant
  
prompt.role: user
extra_info.answer: .0000672
extra_info.question: Convert $\frac{21}{2^2 \cdot 5^7}$ to a terminating decimal.
extra_info.split: test