A swimming pool is 50 meters long. Zhang Xing swims 4 times a day. How many kilometers can he swim in a week?
一个游泳池长50米，张星每天要游4个来回，他一个星期能游多少千米？
<gadget id="calculator">7 / 1_000</gadget>
<output>7/1_000 = around 0.007</output>

<gadget id="calculator">50 * 2 * 4 * (7/1_000)</gadget>
<output>14/5 = around 2.8</output>

<result>14/5 = around 2.8</result>