720/60, when the dividend increases by 120, how much does the quotient increase.
720/60，当被除数增加120时，商增加多少．
<gadget id="calculator">720 + 120</gadget>
<output>840</output>

<gadget id="calculator">840 / 60</gadget>
<output>14</output>

<gadget id="calculator">720 / 60</gadget>
<output>12</output>

<gadget id="calculator">14 - 12</gadget>
<output>2</output>

<result>2</result>