Xiao Ming has to walk 1.2 kilometers from home to school. After he walked 0.5 kilometers, he went home and picked up a book, so how many kilometers did he have to walk more than usual to go to school?
小明从家到学校要走1.2千米．他走了0.5千米后又回家取了一本书，这样他比平时上学要多走的多少千米？
<gadget id="calculator">0.5 * 2</gadget>
<output>1</output>

<result>1</result>