Boss Liu plans to sell a box of pears one by one, and it is expected to sell for 120 yuan. But 10 of them rotted in the middle, and he only sold them for 100 yuan. How many pears were there in total in this box?
刘老板打算把一箱雪梨按个卖，预计卖完能卖到120元．可是中途烂了10个，卖完他只卖到100元，这厢雪梨原来一共有多少个？
<gadget id="calculator">120 - 100</gadget>
<output>20</output>

<gadget id="calculator">20 / 10</gadget>
<output>2</output>

<gadget id="calculator">120 / 2</gadget>
<output>60</output>

<result>60</result>