There are 18 sycamore trees in the campus, the number of cypress trees is 2/3 of sycamore trees, and the number of poplar trees is 1/2 of cypress trees. How many poplar trees are there?
校园里有18棵梧桐树，柏树的棵数是梧桐树的(2/3)，杨树的棵数是柏树的(1/2)，杨树有多少棵？
<gadget id="calculator">2 / 3</gadget>
<output>2/3 = around 0.666667</output>

<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">18 * (2/3) * (1/2)</gadget>
<output>6</output>

<result>6</result>