How much longer is 1 meter than 80 centimeters?
1米比80厘米长多少．
<gadget id="calculator">1 * 100</gadget>
<output>100</output>

<gadget id="calculator">100 - 80</gadget>
<output>20</output>

<gadget id="calculator">20 / 80</gadget>
<output>1/4 = around 0.25</output>

<result>1/4 = around 0.25</result>