Xiaohua is 1.6 meters tall, 0.2 meters shorter than Xiaogang, and 0.3 meters taller than Xiangming. Who is tallest? Who is the shortest? How much taller is the tallest than the shortest?
小华高1.6米，比小刚矮0.2米，比向明高0.3米．谁最高？谁最矮？最高的比最矮的高多少米？
<gadget id="calculator">1.6 + 0.2</gadget>
<output>1.8</output>

<gadget id="calculator">1.6 - 0.3</gadget>
<output>1.3</output>

<gadget id="calculator">1.8 - 1.3</gadget>
<output>0.5</output>

<result>0.5</result>