There are 56 students in the sixth grade of Houcun Primary School, of which boys accounted for (3/7). Later, a few male students were transferred to the school. At this time, male students accounted for (7/15) of the whole class. How many male students are transferred?
后村小学六年级56个学生，其中男生占(3/7)，后来转进几个男同学，这时男同学占全班人数的(7/15)．转进多少个男同学？
<gadget id="calculator">3 / 7</gadget>
<output>3/7 = around 0.428571</output>

<gadget id="calculator">1 - (3/7)</gadget>
<output>4/7 = around 0.571429</output>

<gadget id="calculator">7 / 15</gadget>
<output>7/15 = around 0.466667</output>

<gadget id="calculator">1 - (7/15)</gadget>
<output>8/15 = around 0.533333</output>

<gadget id="calculator">(4/7) / (8/15)</gadget>
<output>15/14 = around 1.071429</output>

<gadget id="calculator">56 * (15/14)</gadget>
<output>60</output>

<gadget id="calculator">60 - 56</gadget>
<output>4</output>

<result>4</result>