A batch of cement, 12 tons are used, and the rest is used (1/4), how many tons of cement are left?
一批水泥，用去12吨，剩下的是用去的(1/4)，剩下水泥多少吨？
<gadget id="calculator">1 / 4</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">12 * (1/4)</gadget>
<output>3</output>

<result>3</result>