Zhangzhuang wants to install street lights on the side of a 120-meter-long street. It plans to install a telephone pole every 12 meters (both ends must be installed). How many telephone poles are needed?
张庄要在一条长120米的街道一旁装路灯，计划每隔12米装一根电线杆(两头都要装)，需要装多少根电线杆？
<gadget id="calculator">120 / 12</gadget>
<output>10</output>

<gadget id="calculator">10 + 1</gadget>
<output>11</output>

<result>11</result>