The number of girls in the fifth grade was 2 more than the number of boys (9/10). Later, 4 girls were transferred. At this time, the ratio of the number of female voices to the number of boys was 19:20. How many boys are there?
五年级女生人数比男生的(9/10)多2人，后来转来4名女生，这时女声人数与男生人数的比是19：20，男生有多少人？
<gadget id="calculator">2 + 4</gadget>
<output>6</output>

<gadget id="calculator">19 / 20</gadget>
<output>19/20 = around 0.95</output>

<gadget id="calculator">9 / 10</gadget>
<output>9/10 = around 0.9</output>

<gadget id="calculator">(19/20) - (9/10)</gadget>
<output>1/20 = around 0.05</output>

<gadget id="calculator">6 / (1/20)</gadget>
<output>120</output>

<result>120</result>