A pile of coal was originally planned to burn 3.5 tons per day, and it can be burned for 64 days. It actually burned 3.2 tons per day. How many days did it actually burn?
一堆煤原计划每天烧3.5吨，可烧64天，实际每天烧3.2吨，实际烧了多少天？
<gadget id="calculator">64 / 3.2</gadget>
<output>20</output>

<gadget id="calculator">3.5 * 20</gadget>
<output>70</output>

<result>70</result>