The Young Pioneers accepted the task of planting a batch of saplings. On the first day, part of them were planted. The ratio of the number of trees that had been planted to the number of trees that had not been planted was 3:4. On the second day, 52 trees were planted. The number of trees is 4 times the number of unplanted trees. How many trees did you plant on the first day?
少先队员接受一批种植树苗的任务，第一天种了一部分，已种完的棵数和未种完的棵数的比是3：4，第二天种52棵，这时已种完的棵数是未种完棵数的4倍．第一天种了多少棵？
<gadget id="calculator">4 + 1</gadget>
<output>5</output>

<gadget id="calculator">4 / 5</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">3 + 4</gadget>
<output>7</output>

<gadget id="calculator">3 / 7</gadget>
<output>3/7 = around 0.428571</output>

<gadget id="calculator">(4/5) - (3/7)</gadget>
<output>13/35 = around 0.371429</output>

<gadget id="calculator">52 / (13/35)</gadget>
<output>140</output>

<gadget id="calculator">140 * (3/7)</gadget>
<output>60</output>

<result>60</result>