A swimming pool is 50 meters long. Xiao Ming swims 4 times a day. How many meters did he swim in total in July?
一个游泳池长50米，小明每天游4个来回，他七月份一共游多少米？
<gadget id="calculator">2 * 4</gadget>
<output>8</output>

<gadget id="calculator">50 * 8 * 31</gadget>
<output>12_400</output>

<result>12_400</result>