To make 3 skipping ropes, you need to buy 6 meters of plastic rope. If you want to make 18 skipping ropes, how many meters of plastic rope do you need to buy?
做3根跳绳要买6米塑料绳，如果要做18根跳绳，需要买多少米塑料绳？
<gadget id="calculator">6 / 3</gadget>
<output>2</output>

<gadget id="calculator">2 * 18</gadget>
<output>36</output>

<result>36</result>