There are 50 students in Class 1 of the sixth grade, among which boys account for 3/5 of the total number. Later, a few girls were transferred, and now the number of girls accounted for the total number (4/9). How many girls are transferred?
六年级一班有学生50人，其中男生占总人数的(3/5)．后来又转来几个女生，这时女生人数就占总人数的(4/9)．转来女生多少人？
<gadget id="calculator">3 / 5</gadget>
<output>3/5 = around 0.6</output>

<gadget id="calculator">4 / 9</gadget>
<output>4/9 = around 0.444444</output>

<gadget id="calculator">1 - (4/9)</gadget>
<output>5/9 = around 0.555556</output>

<gadget id="calculator">(3/5) / (5/9)</gadget>
<output>27/25 = around 1.08</output>

<gadget id="calculator">50 * (27/25)</gadget>
<output>54</output>

<gadget id="calculator">54 - 50</gadget>
<output>4</output>

<result>4</result>