Uncle Zhang picked 144 kilograms of grapes in the morning and another 162 kilograms in the afternoon. He is going to pack these grapes to the market. Each carton can hold 18 kilograms of grapes. How many cartons does Uncle Zhang need to prepare?
张叔叔摘葡萄，上午摘了144千克，下午又摘了162千克．他准备将这些葡萄装箱运往市场，每个纸箱能装18千克葡萄，张叔叔需篓需要准备多少个纸箱？
<gadget id="calculator">144 + 162</gadget>
<output>306</output>

<gadget id="calculator">306 / 18</gadget>
<output>17</output>

<result>17</result>