Grandpa goes to the park every morning to run. His running speed is 105 m/min. After half an hour, how many meters does grandpa run?
爷爷每天早上要到公园去跑步，他跑步的速度是105米/分，半小时后，爷爷跑了多少米？
<gadget id="calculator">105 * 30</gadget>
<output>3_150</output>

<result>3_150</result>