What is the ratio of 20cm:2m?
20cm：2m的比值是多少．
<gadget id="calculator">2 * 100</gadget>
<output>200</output>

<gadget id="calculator">20 / 200</gadget>
<output>1/10 = around 0.1</output>

<result>1/10 = around 0.1</result>