Xiaoxin has to walk 1.2 kilometers from home to school. One day, after walking 0.3 kilometers, he went home to pick up a book. In this way, how many kilometers did he walk to school more than usual.
小新从家到学校要走1.2千米．一天，他走了0.3千米后又回家取了一本书，这样，他比平时上学要多走多少千米．
<gadget id="calculator">0.3 * 2</gadget>
<output>0.6</output>

<result>0.6</result>