Xiaoqiang's home is 2.56 kilometers away from the school. He goes back and forth twice a day, how many kilometers does he have to walk in a week (5 days).
小强家离学校2.56千米，他每天往返两次，一周(按5天)要走多少千米．
<gadget id="calculator">2.56 * 2 * 2 * 5</gadget>
<output>51.2</output>

<result>51.2</result>