The school bought back 18 boxes of chalk, 36 boxes in each box, half of which were used up, how many boxes are left.
学校买回18箱粉笔，每箱36盒，用去了一半，还剩下多少盒．
<gadget id="calculator">18 / 2</gadget>
<output>9</output>

<gadget id="calculator">36 * 9</gadget>
<output>324</output>

<result>324</result>