A runway is 50 meters long. Wang Hua ran back and forth 5 times on this runway. How many meters did he run in total?
一条跑道长50米，王华在这条跑道上跑了5个来回，一共跑了多少米．
<gadget id="calculator">50 * 2 * 5</gadget>
<output>500</output>

<result>500</result>