Tree planting and birth control Hong primary school students planted trees in the suburbs. The third grade planted 46 trees, twice that of the second grade, and the fourth grade planted three times the number of second grade. How many trees are planted in fourth grade?
植树节育红小学学生去郊外植树，三年级级植树46棵，是二年级的2倍，而四年级植的棵数是二年级的3倍．四年级植树多少棵？
<gadget id="calculator">46 / 2</gadget>
<output>23</output>

<gadget id="calculator">23 * 3</gadget>
<output>69</output>

<result>69</result>