During recess, the students were all active on the playground, among which girls accounted for 2/9 of the total number, and later 12 girls came, making the number of girls reach the number of boys (3/7). How many students are there on the playground now?
课间同学们都在操场上活动，其中女生占总人数的(2/9)，后来又来了12个女生，使得女生人数达到男生人数的(3/7)．操场上现在有多少名同学？
<gadget id="calculator">3 / 7</gadget>
<output>3/7 = around 0.428571</output>

<gadget id="calculator">2 / 9</gadget>
<output>2/9 = around 0.222222</output>

<gadget id="calculator">1 - (2/9)</gadget>
<output>7/9 = around 0.777778</output>

<gadget id="calculator">(2/9) / (7/9)</gadget>
<output>2/7 = around 0.285714</output>

<gadget id="calculator">(3/7) - (2/7)</gadget>
<output>1/7 = around 0.142857</output>

<gadget id="calculator">12 / (1/7)</gadget>
<output>84</output>

<gadget id="calculator">84 * (3/7)</gadget>
<output>36</output>

<gadget id="calculator">36 + 84</gadget>
<output>120</output>

<result>120</result>