There are 285 students in the sixth grade in a certain school, the number of fifth grade is the sixth grade (4/5), the fourth grade is more than the fifth grade (1/4), how many more are the fourth grade than the fifth grade?
某校六年级有285人，五年级的人数是六年级的(4/5)，四年级比五年级人数多(1/4)，四年级比五年级多多少人？
<gadget id="calculator">4 / 5</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">1 / 4</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">285 * (4/5) * (1/4)</gadget>
<output>57</output>

<result>57</result>