Xiaohong has to walk 1.2 kilometers from place A to school. After walking 0.3 kilometers, she finds that she has forgotten her math books, and immediately returns to pick up the books by the same route. How many kilometers will she have to walk to school more than usual?
小红从甲地到学校要走1.2千米，当她走了0.3千米后发现数学书忘带了，立即按原路返回取书，这样她要比平时去学校多走多少千米？
<gadget id="calculator">0.3 * 2</gadget>
<output>0.6</output>

<result>0.6</result>