Students in the fourth grade go to the spring outing and buy 120 tickets as a group, totaling 432 yuan, including 2 yuan for one-way tickets and 4 yuan for round-trip tickets. So how much is the difference between one-way tickets and round-trip tickets?
四年级的同学们去春游，按团体购票120张，共432元，其中单程票每张2元，往返票4元，那么单程票和往返票相差多少张？
<gadget id="calculator">4 * 120</gadget>
<output>480</output>

<gadget id="calculator">480 - 432</gadget>
<output>48</output>

<gadget id="calculator">4 - 2</gadget>
<output>2</output>

<gadget id="calculator">48 / 2</gadget>
<output>24</output>

<gadget id="calculator">120 - 24 - 24</gadget>
<output>72</output>

<result>72</result>