There is a batch of coal in the cafeteria, and it is planned to burn 105 kg per day for 30 days. After improving the coal-burning technology, 90 kilograms of coal can be burned every day. How many more days can this batch of coal be burned?
食堂有一批煤，计划每天烧105千克可以烧30天．改进烧煤技术后，每天烧煤90千克，这批煤可以多烧多少天？
<gadget id="calculator">30 / 90</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">105 * (1/3)</gadget>
<output>35</output>

<gadget id="calculator">35 - 30</gadget>
<output>5</output>

<result>5</result>