There are 18 pine saplings, and the number of poplar saplings is 4 times that of pine saplings. How many poplar saplings are there?
松树苗有18棵，杨树苗的棵数是松树苗的4倍，杨树苗有多少棵？
<gadget id="calculator">18 * 4</gadget>
<output>72</output>

<result>72</result>