Xiaoxin has to walk 1.2 kilometers to go home from school. One day after school, he walked 0.4 kilometers away from school, and then returned to school to get an exercise book. How much more kilometers did you walk home this time than usual?
小新从学校回家要走1.2千米路．一天放学后，他从学校出发走了0.4千米后，又返回学校拿一本练习本．这次回家比平时多走多少千米？
<gadget id="calculator">0.4 * 2</gadget>
<output>0.8</output>

<result>0.8</result>