The length of the runway on the school playground is 400 meters a week. Xiao Ming ran 3 laps. How much did he run?
学校操场跑道一周的长是400米，小明跑了3圈，他跑了多少．
<gadget id="calculator">400 * 3</gadget>
<output>1_200</output>

<result>1_200</result>