4 classmates took pictures, one for each two, how many pictures were taken in total.
4个同学照相，每两人照一张，一共照了多少张．
<gadget id="calculator">4 / 2</gadget>
<output>2</output>

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

<result>6</result>