A factory shipped a batch of coal and planned to burn 5 tons per day for 90 days. Actually burn 4.5 tons per day, how many days can it burn?
某工厂运来一批煤，计划每天烧5吨，可以烧90天．实际每天烧4.5吨，可以烧多少天？
<gadget id="calculator">90 / 4.5</gadget>
<output>20</output>

<gadget id="calculator">5 * 20</gadget>
<output>100</output>

<result>100</result>