The starting price of a taxi in a certain place is 8 yuan (within 3 kilometers), and the fare is 2 yuan per kilometer beyond 3 kilometers. Xiao Ming paid a total of 20 yuan for taking a taxi from the pier to his home. About how many kilometers is it from the pier to Xiao Ming's house?
某地出租车起步价为8元(3千米以内)，超出3千米，每千米收费2元．小明打车从码头到家共付费20元．从码头到小明家大约有多少千米？
<gadget id="calculator">20 - 8</gadget>
<output>12</output>

<gadget id="calculator">12 / 2</gadget>
<output>6</output>

<gadget id="calculator">3 + 6</gadget>
<output>9</output>

<result>9</result>