Mom took Xiao Ming to see grandma by long-distance bus. The car traveled an average of 80 kilometers per hour and arrived at grandma's house in 4 hours. How many kilometers did Mom and Xiao Ming travel by car?
妈妈带小明坐长途汽车去看奶奶，汽车平均每小时行80千米，4小时到达奶奶家．妈妈和小明乘车的里程是多少千米？
<gadget id="calculator">80 * 4</gadget>
<output>320</output>

<result>320</result>