The school cafeteria brought a batch of briquettes. It is planned to burn 6 briquettes per day, which can last for 40 days. After the stove is improved, it can be burned for 60 days. How many briquettes are burned every day?
学校食堂运来一批煤球，计划每天烧煤球6块，可烧40天，改进炉灶后，可烧60天，现在每天烧煤球多少块？
<gadget id="calculator">40 / 60</gadget>
<output>2/3 = around 0.666667</output>

<gadget id="calculator">6 * (2/3)</gadget>
<output>4</output>

<result>4</result>